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

1 files changed, 261 insertions, 87 deletions

diff --git a/test/passes/safe-heap_start-function.txt b/test/passes/safe-heap_start-function.txt
index ae7559a97..11b258945 100644
--- a/test/passes/safe-heap_start-function.txt
+++ b/test/passes/safe-heap_start-function.txt
@@ -74,7 +74,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i32.load8_s
    (local.get $2)
@@ -104,7 +106,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i32.load8_u
    (local.get $2)
@@ -134,7 +138,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i32.load16_s align=1
    (local.get $2)
@@ -164,14 +170,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i32.load16_s
    (local.get $2)
@@ -201,7 +211,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i32.load16_u align=1
    (local.get $2)
@@ -231,14 +243,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i32.load16_u
    (local.get $2)
@@ -268,7 +284,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i32.load align=1
    (local.get $2)
@@ -298,14 +316,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i32.load align=2
    (local.get $2)
@@ -335,14 +357,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i32.load
    (local.get $2)
@@ -372,7 +398,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.load8_s
    (local.get $2)
@@ -402,7 +430,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.load8_u
    (local.get $2)
@@ -432,7 +462,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.load16_s align=1
    (local.get $2)
@@ -462,14 +494,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.load16_s
    (local.get $2)
@@ -499,7 +535,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.load16_u align=1
    (local.get $2)
@@ -529,14 +567,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.load16_u
    (local.get $2)
@@ -566,7 +608,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.load32_s align=1
    (local.get $2)
@@ -596,14 +640,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.load32_s align=2
    (local.get $2)
@@ -633,14 +681,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.load32_s
    (local.get $2)
@@ -670,7 +722,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.load32_u align=1
    (local.get $2)
@@ -700,14 +754,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.load32_u align=2
    (local.get $2)
@@ -737,14 +795,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.load32_u
    (local.get $2)
@@ -774,7 +836,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.load align=1
    (local.get $2)
@@ -804,14 +868,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.load align=2
    (local.get $2)
@@ -841,14 +909,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.load align=4
    (local.get $2)
@@ -878,14 +950,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 7)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.load
    (local.get $2)
@@ -915,7 +991,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (f32.load align=1
    (local.get $2)
@@ -945,14 +1023,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f32.load align=2
    (local.get $2)
@@ -982,14 +1064,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f32.load
    (local.get $2)
@@ -1019,7 +1105,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (f64.load align=1
    (local.get $2)
@@ -1049,14 +1137,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f64.load align=2
    (local.get $2)
@@ -1086,14 +1178,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f64.load align=4
    (local.get $2)
@@ -1123,14 +1219,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $2)
     (i32.const 7)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f64.load
    (local.get $2)
@@ -1160,7 +1260,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i32.store8
    (local.get $3)
@@ -1191,7 +1293,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i32.store16 align=1
    (local.get $3)
@@ -1222,14 +1326,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i32.store16
    (local.get $3)
@@ -1260,7 +1368,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i32.store align=1
    (local.get $3)
@@ -1291,14 +1401,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i32.store align=2
    (local.get $3)
@@ -1329,14 +1443,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i32.store
    (local.get $3)
@@ -1367,7 +1485,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.store8
    (local.get $3)
@@ -1398,7 +1518,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.store16 align=1
    (local.get $3)
@@ -1429,14 +1551,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.store16
    (local.get $3)
@@ -1467,7 +1593,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.store32 align=1
    (local.get $3)
@@ -1498,14 +1626,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.store32 align=2
    (local.get $3)
@@ -1536,14 +1668,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.store32
    (local.get $3)
@@ -1574,7 +1710,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (i64.store align=1
    (local.get $3)
@@ -1605,14 +1743,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.store align=2
    (local.get $3)
@@ -1643,14 +1785,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.store align=4
    (local.get $3)
@@ -1681,14 +1827,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 7)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (i64.store
    (local.get $3)
@@ -1719,7 +1869,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (f32.store align=1
    (local.get $3)
@@ -1750,14 +1902,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f32.store align=2
    (local.get $3)
@@ -1788,14 +1944,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f32.store
    (local.get $3)
@@ -1826,7 +1986,9 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (f64.store align=1
    (local.get $3)
@@ -1857,14 +2019,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 1)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f64.store align=2
    (local.get $3)
@@ -1895,14 +2061,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 3)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f64.store align=4
    (local.get $3)
@@ -1933,14 +2103,18 @@
      )
     )
    )
-   (call $segfault)
+   (then
+    (call $segfault)
+   )
   )
   (if
    (i32.and
     (local.get $3)
     (i32.const 7)
    )
-   (call $alignfault)
+   (then
+    (call $alignfault)
+   )
   )
   (f64.store
    (local.get $3)