Rename `wasm2asm` to `wasm2js`, emit ESM by default (#1642)

* Rename the `wasm2asm` tool to `wasm2js`

This commit performs a relatively simple rename of the `wasm2asm` tool to
`wasm2js`. The functionality of the tool doesn't change just yet but it's
intended that we'll start generating an ES module instead of just an `asm.js`
function soon.

* wasm2js: Support `*.wasm` input files

Previously `wasm2js` only supported `*.wast` files but to make it a bit easier
to use in tooling pipelines this commit adds support for reading in a `*.wasm`
file directly. Determining which parser to use depends on the input filename,
where the binary parser is used with `*.wasm` files and the wast parser is used
for all other files.

* wasm2js: Emit ESM imports/exports by default

This commit alters the default behavior of `wasm2js` to emit an ESM by default,
either importing items from the environment or exporting. Items like
initialization of memory are also handled here.

1 files changed, 165 insertions, 0 deletions

diff --git a/test/wasm2js/i64-ctz.2asm.js b/test/wasm2js/i64-ctz.2asm.js
new file mode 100644
index 000000000..000203396
--- /dev/null
+++ b/test/wasm2js/i64-ctz.2asm.js
@@ -0,0 +1,165 @@
+function asmFunc(global, env, buffer) {
+ "use asm";
+ var HEAP8 = new global.Int8Array(buffer);
+ var HEAP16 = new global.Int16Array(buffer);
+ var HEAP32 = new global.Int32Array(buffer);
+ var HEAPU8 = new global.Uint8Array(buffer);
+ var HEAPU16 = new global.Uint16Array(buffer);
+ var HEAPU32 = new global.Uint32Array(buffer);
+ var HEAPF32 = new global.Float32Array(buffer);
+ var HEAPF64 = new global.Float64Array(buffer);
+ var Math_imul = global.Math.imul;
+ var Math_fround = global.Math.fround;
+ var Math_abs = global.Math.abs;
+ var Math_clz32 = global.Math.clz32;
+ var Math_min = global.Math.min;
+ var Math_max = global.Math.max;
+ var Math_floor = global.Math.floor;
+ var Math_ceil = global.Math.ceil;
+ var Math_sqrt = global.Math.sqrt;
+ var abort = env.abort;
+ var nan = global.NaN;
+ var infinity = global.Infinity;
+ var i64toi32_i32$HIGH_BITS = 0;
+ function popcnt64($0, $0$hi) {
+  $0 = $0 | 0;
+  $0$hi = $0$hi | 0;
+  var i64toi32_i32$0 = 0, i64toi32_i32$1 = 0;
+  i64toi32_i32$0 = $0$hi;
+  i64toi32_i32$0 = i64toi32_i32$0;
+  i64toi32_i32$0 = __wasm_popcnt_i64($0 | 0, i64toi32_i32$0 | 0) | 0;
+  i64toi32_i32$1 = i64toi32_i32$HIGH_BITS;
+  i64toi32_i32$1 = i64toi32_i32$1;
+  i64toi32_i32$0 = i64toi32_i32$0;
+  i64toi32_i32$HIGH_BITS = i64toi32_i32$1;
+  return i64toi32_i32$0 | 0;
+ }
+ 
+ function ctz64($0, $0$hi) {
+  $0 = $0 | 0;
+  $0$hi = $0$hi | 0;
+  var i64toi32_i32$0 = 0, i64toi32_i32$1 = 0;
+  i64toi32_i32$0 = $0$hi;
+  i64toi32_i32$0 = i64toi32_i32$0;
+  i64toi32_i32$0 = __wasm_ctz_i64($0 | 0, i64toi32_i32$0 | 0) | 0;
+  i64toi32_i32$1 = i64toi32_i32$HIGH_BITS;
+  i64toi32_i32$1 = i64toi32_i32$1;
+  i64toi32_i32$0 = i64toi32_i32$0;
+  i64toi32_i32$HIGH_BITS = i64toi32_i32$1;
+  return i64toi32_i32$0 | 0;
+ }
+ 
+ function __wasm_ctz_i64(var$0, var$0$hi) {
+  var$0 = var$0 | 0;
+  var$0$hi = var$0$hi | 0;
+  var i64toi32_i32$0 = 0, i64toi32_i32$5 = 0, i64toi32_i32$3 = 0, i64toi32_i32$4 = 0, i64toi32_i32$2 = 0, i64toi32_i32$1 = 0, $10 = 0, $5$hi = 0, $8$hi = 0;
+  i64toi32_i32$0 = var$0$hi;
+  i64toi32_i32$0 = i64toi32_i32$0;
+  if (((var$0 | i64toi32_i32$0 | 0 | 0) == (0 | 0) | 0) == (0 | 0)) {
+   i64toi32_i32$0 = var$0$hi;
+   i64toi32_i32$0 = i64toi32_i32$0;
+   i64toi32_i32$2 = var$0;
+   i64toi32_i32$1 = 4294967295;
+   i64toi32_i32$3 = 4294967295;
+   i64toi32_i32$4 = i64toi32_i32$2 + i64toi32_i32$3 | 0;
+   i64toi32_i32$5 = i64toi32_i32$0 + i64toi32_i32$1 | 0;
+   if (i64toi32_i32$4 >>> 0 < i64toi32_i32$3 >>> 0) i64toi32_i32$5 = i64toi32_i32$5 + 1 | 0;
+   $5$hi = i64toi32_i32$5;
+   i64toi32_i32$5 = var$0$hi;
+   i64toi32_i32$5 = $5$hi;
+   i64toi32_i32$0 = i64toi32_i32$4;
+   i64toi32_i32$2 = var$0$hi;
+   i64toi32_i32$3 = var$0;
+   i64toi32_i32$2 = i64toi32_i32$5 ^ i64toi32_i32$2 | 0;
+   i64toi32_i32$2 = i64toi32_i32$2;
+   i64toi32_i32$0 = i64toi32_i32$0 ^ i64toi32_i32$3 | 0;
+   i64toi32_i32$3 = Math_clz32(i64toi32_i32$2);
+   i64toi32_i32$5 = 0;
+   if ((i64toi32_i32$3 | 0) == (32 | 0)) $10 = Math_clz32(i64toi32_i32$0) + 32 | 0; else $10 = i64toi32_i32$3;
+   $8$hi = i64toi32_i32$5;
+   i64toi32_i32$5 = 0;
+   i64toi32_i32$0 = 63;
+   i64toi32_i32$2 = $8$hi;
+   i64toi32_i32$3 = $10;
+   i64toi32_i32$1 = i64toi32_i32$0 - i64toi32_i32$3 | 0;
+   i64toi32_i32$4 = (i64toi32_i32$0 >>> 0 < i64toi32_i32$3 >>> 0) + i64toi32_i32$2 | 0;
+   i64toi32_i32$4 = i64toi32_i32$5 - i64toi32_i32$4 | 0;
+   i64toi32_i32$4 = i64toi32_i32$4;
+   i64toi32_i32$0 = i64toi32_i32$1;
+   i64toi32_i32$HIGH_BITS = i64toi32_i32$4;
+   return i64toi32_i32$0 | 0;
+  }
+  i64toi32_i32$0 = 0;
+  i64toi32_i32$0 = i64toi32_i32$0;
+  i64toi32_i32$0 = i64toi32_i32$0;
+  i64toi32_i32$4 = 64;
+  i64toi32_i32$HIGH_BITS = i64toi32_i32$0;
+  return i64toi32_i32$4 | 0;
+ }
+ 
+ function __wasm_popcnt_i64(var$0, var$0$hi) {
+  var$0 = var$0 | 0;
+  var$0$hi = var$0$hi | 0;
+  var i64toi32_i32$0 = 0, i64toi32_i32$2 = 0, i64toi32_i32$4 = 0, i64toi32_i32$5 = 0, i64toi32_i32$3 = 0, i64toi32_i32$1 = 0, var$1$hi = 0, var$1 = 0, $5 = 0, $5$hi = 0, $4 = 0, $9$hi = 0;
+  label$1 : {
+   label$2 : do {
+    i64toi32_i32$0 = var$1$hi;
+    i64toi32_i32$0 = var$0$hi;
+    i64toi32_i32$0 = i64toi32_i32$0;
+    $4 = (var$0 | i64toi32_i32$0 | 0 | 0) == (0 | 0);
+    i64toi32_i32$0 = var$1$hi;
+    $5 = var$1;
+    $5$hi = i64toi32_i32$0;
+    if ($4) break label$1;
+    i64toi32_i32$0 = $5$hi;
+    i64toi32_i32$0 = i64toi32_i32$0;
+    i64toi32_i32$0 = var$0$hi;
+    i64toi32_i32$0 = i64toi32_i32$0;
+    i64toi32_i32$0 = i64toi32_i32$0;
+    i64toi32_i32$2 = var$0;
+    i64toi32_i32$1 = 0;
+    i64toi32_i32$3 = 1;
+    i64toi32_i32$4 = i64toi32_i32$2 - i64toi32_i32$3 | 0;
+    i64toi32_i32$5 = (i64toi32_i32$2 >>> 0 < i64toi32_i32$3 >>> 0) + i64toi32_i32$1 | 0;
+    i64toi32_i32$5 = i64toi32_i32$0 - i64toi32_i32$5 | 0;
+    $9$hi = i64toi32_i32$5;
+    i64toi32_i32$5 = i64toi32_i32$0;
+    i64toi32_i32$0 = i64toi32_i32$2;
+    i64toi32_i32$2 = $9$hi;
+    i64toi32_i32$3 = i64toi32_i32$4;
+    i64toi32_i32$2 = i64toi32_i32$5 & i64toi32_i32$2 | 0;
+    i64toi32_i32$2 = i64toi32_i32$2;
+    var$0 = i64toi32_i32$0 & i64toi32_i32$4 | 0;
+    var$0$hi = i64toi32_i32$2;
+    i64toi32_i32$2 = var$1$hi;
+    i64toi32_i32$2 = i64toi32_i32$2;
+    i64toi32_i32$5 = var$1;
+    i64toi32_i32$0 = 0;
+    i64toi32_i32$3 = 1;
+    i64toi32_i32$1 = i64toi32_i32$5 + i64toi32_i32$3 | 0;
+    i64toi32_i32$4 = i64toi32_i32$2 + i64toi32_i32$0 | 0;
+    if (i64toi32_i32$1 >>> 0 < i64toi32_i32$3 >>> 0) i64toi32_i32$4 = i64toi32_i32$4 + 1 | 0;
+    i64toi32_i32$4 = i64toi32_i32$4;
+    var$1 = i64toi32_i32$1;
+    var$1$hi = i64toi32_i32$4;
+    continue label$2;
+    break label$2;
+   } while (1);
+  };
+  i64toi32_i32$4 = $5$hi;
+  i64toi32_i32$4 = i64toi32_i32$4;
+  i64toi32_i32$5 = $5;
+  i64toi32_i32$HIGH_BITS = i64toi32_i32$4;
+  return i64toi32_i32$5 | 0;
+ }
+ 
+ return {
+  a: popcnt64, 
+  b: ctz64
+ };
+}
+
+const memasmFunc = new ArrayBuffer(65536);
+const retasmFunc = asmFunc({Math,Int8Array,Uint8Array,Int16Array,Uint16Array,Int32Array,Uint32Array,Float32Array,Float64Array,NaN,Infinity}, {abort:function() { throw new Error('abort'); }},memasmFunc);
+export const a = retasmFunc.a;
+export const b = retasmFunc.b;