Require `then` and `else` with `if` (#6201)

We previously supported (and primarily used) a non-standard text format for
conditionals in which the condition, if-true expression, and if-false expression
were all simply s-expression children of the `if` expression. The standard text
format, however, requires the use of `then` and `else` forms to introduce the
if-true and if-false arms of the conditional. Update the legacy text parser to
require the standard format and update all tests to match. Update the printer to
print the standard format as well.

The .wast and .wat test inputs were mechanically updated with this script:
https://gist.github.com/tlively/85ae7f01f92f772241ec994c840ccbb1

11 files changed, 303 insertions, 187 deletions

diff --git a/test/wasm2js/br.2asm.js b/test/wasm2js/br.2asm.js
index d9648261b..eb6dedfff 100644
--- a/test/wasm2js/br.2asm.js
+++ b/test/wasm2js/br.2asm.js
@@ -204,7 +204,7 @@ function asmFunc(imports) {
  }
  
  function $24() {
-  var $0 = 0, $5_1 = 0;
+  var $0 = 0, $1_1 = 0;
   if_ : {
    $0 = 2;
    break if_;
@@ -215,15 +215,15 @@ function asmFunc(imports) {
  function $25($0, $1_1) {
   $0 = $0 | 0;
   $1_1 = $1_1 | 0;
-  var $3_1 = 0, $7_1 = 0;
+  var $3_1 = 0, $5_1 = 0;
   block : {
    if ($0) {
     $3_1 = 3;
     break block;
    } else {
-    $7_1 = $1_1
+    $5_1 = $1_1
    }
-   $3_1 = $7_1;
+   $3_1 = $5_1;
   }
   return $3_1 | 0;
  }
@@ -231,17 +231,17 @@ function asmFunc(imports) {
  function $26($0, $1_1) {
   $0 = $0 | 0;
   $1_1 = $1_1 | 0;
-  var $6_1 = 0, $7_1 = 0;
+  var $4_1 = 0, $5_1 = 0;
   block : {
    if ($0) {
-    $7_1 = $1_1
+    $5_1 = $1_1
    } else {
-    $6_1 = 4;
+    $4_1 = 4;
     break block;
    }
-   $6_1 = $7_1;
+   $4_1 = $5_1;
   }
-  return $6_1 | 0;
+  return $4_1 | 0;
  }
  
  function $27($0, $1_1) {
diff --git a/test/wasm2js/br_table.2asm.js b/test/wasm2js/br_table.2asm.js
index 668391c02..c3fa8e31d 100644
--- a/test/wasm2js/br_table.2asm.js
+++ b/test/wasm2js/br_table.2asm.js
@@ -12685,7 +12685,7 @@ function asmFunc(imports) {
  }
  
  function $31() {
-  var $1_1 = 0, $6_1 = 0;
+  var $1_1 = 0, $2_1 = 0;
   if_ : {
    $1_1 = 2;
    switch (0 | 0) {
@@ -12699,7 +12699,7 @@ function asmFunc(imports) {
  function $32($0, $1_1) {
   $0 = $0 | 0;
   $1_1 = $1_1 | 0;
-  var $4_1 = 0, $8_1 = 0;
+  var $4_1 = 0, $6_1 = 0;
   block : {
    if ($0) {
     $4_1 = 3;
@@ -12708,9 +12708,9 @@ function asmFunc(imports) {
      break block;
     };
    } else {
-    $8_1 = $1_1
+    $6_1 = $1_1
    }
-   $4_1 = $8_1;
+   $4_1 = $6_1;
   }
   return $4_1 | 0;
  }
@@ -12718,15 +12718,15 @@ function asmFunc(imports) {
  function $33($0, $1_1) {
   $0 = $0 | 0;
   $1_1 = $1_1 | 0;
-  var $6_1 = 0, $7_1 = 0, $8_1 = 0, $9_1 = 0;
+  var $4_1 = 0, $5_1 = 0, $6_1 = 0, $7_1 = 0;
   block : {
    if_ : {
     if ($0) {
-     $9_1 = $1_1
+     $7_1 = $1_1
     } else {
-     $6_1 = 4;
-     $7_1 = $6_1;
-     $8_1 = $6_1;
+     $4_1 = 4;
+     $5_1 = $4_1;
+     $6_1 = $4_1;
      switch (0 | 0) {
      case 0:
       break block;
@@ -12734,11 +12734,11 @@ function asmFunc(imports) {
       break if_;
      };
     }
-    $8_1 = $9_1;
+    $6_1 = $7_1;
    }
-   $7_1 = $8_1;
+   $5_1 = $6_1;
   }
-  return $7_1 | 0;
+  return $5_1 | 0;
  }
  
  function $34($0, $1_1) {
diff --git a/test/wasm2js/br_table_temp.wast b/test/wasm2js/br_table_temp.wast
index 1ddff07ca..2c49ca9be 100644
--- a/test/wasm2js/br_table_temp.wast
+++ b/test/wasm2js/br_table_temp.wast
@@ -910,8 +910,12 @@
     (block i32
       (if i32
         (br_table 0 (i32.const 2) (i32.const 0))
-        (i32.const 0)
-        (i32.const 1)
+        (then
+          (i32.const 0)
+        )
+        (else
+          (i32.const 1)
+        )
       )
     )
   )
@@ -919,8 +923,12 @@
     (block i32
       (if i32
         (local.get 0)
-        (br_table 1 (i32.const 3) (i32.const 0))
-        (local.get 1)
+        (then
+          (br_table 1 (i32.const 3) (i32.const 0))
+        )
+        (else
+          (local.get 1)
+        )
       )
     )
   )
@@ -928,8 +936,12 @@
     (block i32
       (if i32
         (local.get 0)
-        (local.get 1)
-        (br_table 1 0 (i32.const 4) (i32.const 0))
+        (then
+          (local.get 1)
+        )
+        (else
+          (br_table 1 0 (i32.const 4) (i32.const 0))
+        )
       )
     )
   )
diff --git a/test/wasm2js/deterministic.wast b/test/wasm2js/deterministic.wast
index 67caefbad..6e2322201 100644
--- a/test/wasm2js/deterministic.wast
+++ b/test/wasm2js/deterministic.wast
@@ -7,7 +7,9 @@
     (global.get $global$0)
     (i32.load (i32.const 0))
    )
-   (unreachable)
+   (then
+    (unreachable)
+   )
   )
   (i32.const 1)
  )
diff --git a/test/wasm2js/emscripten.wast b/test/wasm2js/emscripten.wast
index 823297476..453c9d312 100644
--- a/test/wasm2js/emscripten.wast
+++ b/test/wasm2js/emscripten.wast
@@ -75,58 +75,94 @@
    (i32.add (i32.const 9) (i32.const 10))
   )
   (if (i32.eq (i32.load (i32.const 100)) (i32.const 1))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_s (i32.load (i32.const 104)) (i32.const 2))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_u (i32.load (i32.const 108)) (i32.const 3))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.eq (i32.load16_s (i32.const 112)) (i32.const 1))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_s (i32.load16_s (i32.const 116)) (i32.const 2))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_s (i32.load16_u (i32.const 120)) (i32.const 2))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_u (i32.load16_s (i32.const 124)) (i32.const 3))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_u (i32.load16_u (i32.const 128)) (i32.const 3))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_s (i32.load8_s (i32.const 132)) (i32.const 2))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_s (i32.load8_u (i32.const 136)) (i32.const 2))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_u (i32.load8_s (i32.const 140)) (i32.const 3))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.lt_u (i32.load8_u (i32.const 144)) (i32.const 3))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.shr_u (call $bools (i32.const 314159)) (i32.const 7))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.shr_s (call $bools (i32.const 314159)) (i32.const 8))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.trunc_f32_u (call $getf32))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.trunc_f32_s (call $getf32))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.trunc_f64_u (call $getf64))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if (i32.trunc_f64_s (call $getf64))
-   (call  $bar)
+   (then
+    (call  $bar)
+   )
   )
   (if
     (i32.add
@@ -136,7 +172,9 @@
       )
       (call $geti32)
     )
-    (call $bar)
+    (then
+      (call $bar)
+    )
   )
   (if
     (i32.add
@@ -146,7 +184,9 @@
         (call $geti32)
       )
     )
-    (call $bar)
+    (then
+      (call $bar)
+    )
   )
   (if
     (i32.add
@@ -159,7 +199,9 @@
         (call $geti32)
       )
     )
-    (call $bar)
+    (then
+      (call $bar)
+    )
   )
   (if
     (i32.add
@@ -184,7 +226,9 @@
         )
       )
     )
-    (call $bar)
+    (then
+      (call $bar)
+    )
   )
  )
  (func $geti32 (result i32)
@@ -230,11 +274,15 @@
   (drop (call $bools (i32.xor (local.get $x) (i32.const 1))))
   (if
     (i32.xor (local.get $x) (i32.const 1))
-    (drop (call $bools (i32.const 2)))
+    (then
+      (drop (call $bools (i32.const 2)))
+    )
   )
   (if
     (i32.xor (local.get $x) (i32.const 2))
-    (drop (call $bools (i32.const 2)))
+    (then
+      (drop (call $bools (i32.const 2)))
+    )
   )
   (drop (call $bools (i32.eqz (i32.xor (local.get $x) (i32.const 1)))))
   (unreachable)
diff --git a/test/wasm2js/fac.2asm.js b/test/wasm2js/fac.2asm.js
index b1765575f..f87d217ba 100644
--- a/test/wasm2js/fac.2asm.js
+++ b/test/wasm2js/fac.2asm.js
@@ -17,33 +17,30 @@ function asmFunc(imports) {
  function $0($0_1, $0$hi) {
   $0_1 = $0_1 | 0;
   $0$hi = $0$hi | 0;
-  var i64toi32_i32$3 = 0, i64toi32_i32$5 = 0, i64toi32_i32$2 = 0, i64toi32_i32$1 = 0, $12 = 0, $12$hi = 0, $8 = 0, $8$hi = 0;
-  i64toi32_i32$2 = $0_1;
+  var i64toi32_i32$3 = 0, i64toi32_i32$5 = 0, i64toi32_i32$1 = 0, $8 = 0, $8$hi = 0, $6 = 0, $6$hi = 0;
   i64toi32_i32$1 = 0;
   i64toi32_i32$3 = 0;
-  if ((i64toi32_i32$2 | 0) == (i64toi32_i32$3 | 0) & ($0$hi | 0) == (i64toi32_i32$1 | 0) | 0) {
-   i64toi32_i32$2 = 0;
-   $12 = 1;
-   $12$hi = i64toi32_i32$2;
+  if (($0_1 | 0) == (i64toi32_i32$3 | 0) & ($0$hi | 0) == (i64toi32_i32$1 | 0) | 0) {
+   $8 = 1;
+   $8$hi = 0;
   } else {
-   i64toi32_i32$2 = $0$hi;
    i64toi32_i32$3 = $0_1;
    i64toi32_i32$1 = 1;
    i64toi32_i32$5 = (i64toi32_i32$3 >>> 0 < i64toi32_i32$1 >>> 0) + 0 | 0;
    i64toi32_i32$5 = $0$hi - i64toi32_i32$5 | 0;
    i64toi32_i32$5 = $0(i64toi32_i32$3 - i64toi32_i32$1 | 0 | 0, i64toi32_i32$5 | 0) | 0;
    i64toi32_i32$3 = i64toi32_i32$HIGH_BITS;
-   $8 = i64toi32_i32$5;
-   $8$hi = i64toi32_i32$3;
+   $6 = i64toi32_i32$5;
+   $6$hi = i64toi32_i32$3;
    i64toi32_i32$3 = $0$hi;
-   i64toi32_i32$5 = $8$hi;
-   i64toi32_i32$5 = __wasm_i64_mul($0_1 | 0, i64toi32_i32$3 | 0, $8 | 0, i64toi32_i32$5 | 0) | 0;
+   i64toi32_i32$5 = $6$hi;
+   i64toi32_i32$5 = __wasm_i64_mul($0_1 | 0, $0$hi | 0, $6 | 0, i64toi32_i32$5 | 0) | 0;
    i64toi32_i32$3 = i64toi32_i32$HIGH_BITS;
-   $12 = i64toi32_i32$5;
-   $12$hi = i64toi32_i32$3;
+   $8 = i64toi32_i32$5;
+   $8$hi = i64toi32_i32$3;
   }
-  i64toi32_i32$3 = $12$hi;
-  i64toi32_i32$5 = $12;
+  i64toi32_i32$3 = $8$hi;
+  i64toi32_i32$5 = $8;
   i64toi32_i32$HIGH_BITS = i64toi32_i32$3;
   return i64toi32_i32$5 | 0;
  }
@@ -51,33 +48,30 @@ function asmFunc(imports) {
  function fac_rec_named(n, n$hi) {
   n = n | 0;
   n$hi = n$hi | 0;
-  var i64toi32_i32$3 = 0, i64toi32_i32$5 = 0, i64toi32_i32$2 = 0, i64toi32_i32$1 = 0, $12 = 0, $12$hi = 0, $8 = 0, $8$hi = 0;
-  i64toi32_i32$2 = n;
+  var i64toi32_i32$3 = 0, i64toi32_i32$5 = 0, i64toi32_i32$1 = 0, $8 = 0, $8$hi = 0, $6 = 0, $6$hi = 0;
   i64toi32_i32$1 = 0;
   i64toi32_i32$3 = 0;
-  if ((i64toi32_i32$2 | 0) == (i64toi32_i32$3 | 0) & (n$hi | 0) == (i64toi32_i32$1 | 0) | 0) {
-   i64toi32_i32$2 = 0;
-   $12 = 1;
-   $12$hi = i64toi32_i32$2;
+  if ((n | 0) == (i64toi32_i32$3 | 0) & (n$hi | 0) == (i64toi32_i32$1 | 0) | 0) {
+   $8 = 1;
+   $8$hi = 0;
   } else {
-   i64toi32_i32$2 = n$hi;
    i64toi32_i32$3 = n;
    i64toi32_i32$1 = 1;
    i64toi32_i32$5 = (i64toi32_i32$3 >>> 0 < i64toi32_i32$1 >>> 0) + 0 | 0;
    i64toi32_i32$5 = n$hi - i64toi32_i32$5 | 0;
    i64toi32_i32$5 = fac_rec_named(i64toi32_i32$3 - i64toi32_i32$1 | 0 | 0, i64toi32_i32$5 | 0) | 0;
    i64toi32_i32$3 = i64toi32_i32$HIGH_BITS;
-   $8 = i64toi32_i32$5;
-   $8$hi = i64toi32_i32$3;
+   $6 = i64toi32_i32$5;
+   $6$hi = i64toi32_i32$3;
    i64toi32_i32$3 = n$hi;
-   i64toi32_i32$5 = $8$hi;
-   i64toi32_i32$5 = __wasm_i64_mul(n | 0, i64toi32_i32$3 | 0, $8 | 0, i64toi32_i32$5 | 0) | 0;
+   i64toi32_i32$5 = $6$hi;
+   i64toi32_i32$5 = __wasm_i64_mul(n | 0, n$hi | 0, $6 | 0, i64toi32_i32$5 | 0) | 0;
    i64toi32_i32$3 = i64toi32_i32$HIGH_BITS;
-   $12 = i64toi32_i32$5;
-   $12$hi = i64toi32_i32$3;
+   $8 = i64toi32_i32$5;
+   $8$hi = i64toi32_i32$3;
   }
-  i64toi32_i32$3 = $12$hi;
-  i64toi32_i32$5 = $12;
+  i64toi32_i32$3 = $8$hi;
+  i64toi32_i32$5 = $8;
   i64toi32_i32$HIGH_BITS = i64toi32_i32$3;
   return i64toi32_i32$5 | 0;
  }
diff --git a/test/wasm2js/forward.2asm.js b/test/wasm2js/forward.2asm.js
index dab073477..053f0f993 100644
--- a/test/wasm2js/forward.2asm.js
+++ b/test/wasm2js/forward.2asm.js
@@ -12,24 +12,24 @@ function asmFunc(imports) {
  var Math_sqrt = Math.sqrt;
  function even(n) {
   n = n | 0;
-  var $10 = 0;
+  var $6 = 0;
   if ((n | 0) == (0 | 0)) {
-   $10 = 1
+   $6 = 1
   } else {
-   $10 = odd(n - 1 | 0 | 0) | 0
+   $6 = odd(n - 1 | 0 | 0) | 0
   }
-  return $10 | 0;
+  return $6 | 0;
  }
  
  function odd(n) {
   n = n | 0;
-  var $10 = 0;
+  var $6 = 0;
   if ((n | 0) == (0 | 0)) {
-   $10 = 0
+   $6 = 0
   } else {
-   $10 = even(n - 1 | 0 | 0) | 0
+   $6 = even(n - 1 | 0 | 0) | 0
   }
-  return $10 | 0;
+  return $6 | 0;
  }
  
  return {
diff --git a/test/wasm2js/if_unreachable.wast b/test/wasm2js/if_unreachable.wast
index 11b41d16e..65cd4e119 100644
--- a/test/wasm2js/if_unreachable.wast
+++ b/test/wasm2js/if_unreachable.wast
@@ -7,13 +7,17 @@
     (i32.const 0)
     (i32.const 48)
    )
-   (block $label$2
-    (br_if $label$2
-     (i32.const 0)
+   (then
+    (block $label$2
+     (br_if $label$2
+      (i32.const 0)
+     )
+     (unreachable)
     )
+   )
+   (else
     (unreachable)
    )
-   (unreachable)
   )
   (unreachable)
  )
diff --git a/test/wasm2js/stack-modified.wast b/test/wasm2js/stack-modified.wast
index b3ede2380..1ba9f30a8 100644
--- a/test/wasm2js/stack-modified.wast
+++ b/test/wasm2js/stack-modified.wast
@@ -21,18 +21,22 @@
       (local.get $var$1)
       (i64.const 0)
      )
-     (br $label$1)
-     (block $label$5
-      (local.set $var$2
-       (i64.mul
-        (local.get $var$1)
-        (local.get $var$2)
+     (then
+      (br $label$1)
+     )
+     (else
+      (block $label$5
+       (local.set $var$2
+        (i64.mul
+         (local.get $var$1)
+         (local.get $var$2)
+        )
        )
-      )
-      (local.set $var$1
-       (i64.sub
-        (local.get $var$1)
-        (i64.const 1)
+       (local.set $var$1
+        (i64.sub
+         (local.get $var$1)
+         (i64.const 1)
+        )
        )
       )
      )
@@ -58,18 +62,22 @@
       (local.get $var$1)
       (i64.const 0)
      )
-     (br $label$1)
-     (block
-      (local.set $var$2
-       (i64.mul
-        (local.get $var$1)
-        (local.get $var$2)
+     (then
+      (br $label$1)
+     )
+     (else
+      (block
+       (local.set $var$2
+        (i64.mul
+         (local.get $var$1)
+         (local.get $var$2)
+        )
        )
-      )
-      (local.set $var$1
-       (i64.sub
-        (local.get $var$1)
-        (i64.const 1)
+       (local.set $var$1
+        (i64.sub
+         (local.get $var$1)
+         (i64.const 1)
+        )
        )
       )
      )
@@ -95,18 +103,22 @@
       (local.get $var$1)
       (i64.const 0)
      )
-     (br $label$1)
-     (block
-      (local.set $var$2
-       (i64.mul
-        (local.get $var$1)
-        (local.get $var$2)
+     (then
+      (br $label$1)
+     )
+     (else
+      (block
+       (local.set $var$2
+        (i64.mul
+         (local.get $var$1)
+         (local.get $var$2)
+        )
        )
-      )
-      (local.set $var$1
-       (i64.sub
-        (local.get $var$1)
-        (i64.const 1)
+       (local.set $var$1
+        (i64.sub
+         (local.get $var$1)
+         (i64.const 1)
+        )
        )
       )
      )
@@ -132,18 +144,22 @@
       (local.get $var$1)
       (i64.const 0)
      )
-     (br $label$1)
-     (block
-      (local.set $var$2
-       (i64.mul
-        (local.get $var$1)
-        (local.get $var$2)
+     (then
+      (br $label$1)
+     )
+     (else
+      (block
+       (local.set $var$2
+        (i64.mul
+         (local.get $var$1)
+         (local.get $var$2)
+        )
        )
-      )
-      (local.set $var$1
-       (i64.sub
-        (local.get $var$1)
-        (i64.const 1)
+       (local.set $var$1
+        (i64.sub
+         (local.get $var$1)
+         (i64.const 1)
+        )
        )
       )
      )
@@ -169,18 +185,22 @@
       (local.get $var$1)
       (i64.const 0)
      )
-     (br $label$1)
-     (block
-      (local.set $var$2
-       (i64.mul
-        (local.get $var$1)
-        (local.get $var$2)
+     (then
+      (br $label$1)
+     )
+     (else
+      (block
+       (local.set $var$2
+        (i64.mul
+         (local.get $var$1)
+         (local.get $var$2)
+        )
        )
-      )
-      (local.set $var$1
-       (i64.sub
-        (local.get $var$1)
-        (i64.const 1)
+       (local.set $var$1
+        (i64.sub
+         (local.get $var$1)
+         (i64.const 1)
+        )
        )
       )
      )
diff --git a/test/wasm2js/unreachable-get-cycle.wast b/test/wasm2js/unreachable-get-cycle.wast
index 6fc714a39..3a25fea72 100644
--- a/test/wasm2js/unreachable-get-cycle.wast
+++ b/test/wasm2js/unreachable-get-cycle.wast
@@ -10,25 +10,33 @@
     )
     (i32.const 0)
    )
-   (loop $label$3
-    (block $label$4
-     (f32.store offset=22 align=2
-      (i32.const 0)
-      (local.get $2)
-     )
-     (drop
-      (local.tee $2
-       (if (result f32)
-        (i32.const -19666)
-        (local.get $2)
-        (unreachable)
+   (then
+    (loop $label$3
+     (block $label$4
+      (f32.store offset=22 align=2
+       (i32.const 0)
+       (local.get $2)
+      )
+      (drop
+       (local.tee $2
+        (if (result f32)
+         (i32.const -19666)
+         (then
+          (local.get $2)
+         )
+         (else
+          (unreachable)
+         )
+        )
        )
       )
      )
+     (br $label$3)
     )
-    (br $label$3)
    )
-   (i64.const 1)
+   (else
+    (i64.const 1)
+   )
   )
  )
 )
diff --git a/test/wasm2js/unreachable-later.wast b/test/wasm2js/unreachable-later.wast
index 0af552212..49a7cdb85 100644
--- a/test/wasm2js/unreachable-later.wast
+++ b/test/wasm2js/unreachable-later.wast
@@ -5,14 +5,18 @@
  (func $0 (; 0 ;) (type $0) (param $0 i32) (result i32)
   (if
    (global.get $global$0)
-   (return
-    (local.get $0)
+   (then
+    (return
+     (local.get $0)
+    )
    )
   )
   (if
    (global.get $global$0)
-   (return
-    (local.get $0)
+   (then
+    (return
+     (local.get $0)
+    )
    )
   )
   (global.set $global$0
@@ -29,8 +33,10 @@
           (block $label$4 (result i32)
            (if
             (global.get $global$0)
-            (return
-             (local.get $0)
+            (then
+             (return
+              (local.get $0)
+             )
             )
            )
            (drop
@@ -38,48 +44,70 @@
              (block $label$6 (result i32)
               (if
                (global.get $global$0)
-               (return
-                (local.get $0)
+               (then
+                (return
+                 (local.get $0)
+                )
                )
               )
               (i32.const 65445)
              )
-             (block (result f32)
-              (if
-               (global.get $global$0)
-               (return
-                (local.get $0)
+             (then
+              (block (result f32)
+               (if
+                (global.get $global$0)
+                (then
+                 (return
+                  (local.get $0)
+                 )
+                )
                )
+               (f32.const 0)
               )
-              (f32.const 0)
              )
-             (f32.const 1)
+             (else
+              (f32.const 1)
+             )
             )
            )
            (if
             (global.get $global$0)
-            (return
-             (local.get $0)
+            (then
+             (return
+              (local.get $0)
+             )
             )
            )
            (i32.const 1)
           )
-          (i32.const 32)
-          (i32.const 0)
+          (then
+           (i32.const 32)
+          )
+          (else
+           (i32.const 0)
+          )
          )
         )
        )
        (i32.const 1)
       )
      )
-     (i32.const 0)
-     (i32.const 1)
+     (then
+      (i32.const 0)
+     )
+     (else
+      (i32.const 1)
+     )
+    )
+   )
+   (then
+    (return
+     (i32.const -255)
     )
    )
-   (return
-    (i32.const -255)
+   (else
+    (unreachable)
    )
-   (unreachable)
   )
  )
 )