[wasm][asm.js] Fix errata 5.4, allow fround on int literal.s

asm.js errata on section 5.4 allows fround of numeric literals
without '.'.

BUG=v8:4203
R=titzer@chromium.org

Review-Url: https://codereview.chromium.org/2552243002
Cr-Commit-Position: refs/heads/master@{#41510}

src/asmjs/asm-typer.cc

@@ -2814,14 +2814,12 @@ AsmType* AsmTyper::VariableTypeAnnotations(
          "to fround.");
   }
 
-  // Float constants must contain dots in local, but not in globals.
-  if (mutability_type == VariableInfo::kLocal) {
-    if (!src_expr->raw_value()->ContainsDot()) {
-      FAIL(initializer,
-           "Invalid float type annotation - expected literal argument to be a "
-           "floating point literal.");
-    }
-  }
+  // ERRATA: 5.4
+  // According to the spec: float constants must contain dots in local,
+  // but not in globals.
+  // However, the errata doc (and actual programs), use integer values
+  // with fround(..).
+  // Skipping the check that would go here to enforce this.
 
   return AsmType::Float();
 }

test/mjsunit/wasm/asm-wasm.js

@@ -1649,6 +1649,19 @@ function TestDotfulFloat(stdlib) {
 assertWasm(55, TestDotfulFloat);
 
 
+function TestDotfulLocalFloat(stdlib) {
+  "use asm";
+  var fround = stdlib.Math.fround;
+  function caller() {
+    var foo = fround(55.0);
+    return +foo;
+  }
+  return {caller: caller};
+}
+
+assertWasm(55, TestDotfulLocalFloat);
+
+
 function TestDotlessFloat(stdlib) {
   "use asm";
   var fround = stdlib.Math.fround;
@@ -1662,6 +1675,19 @@ function TestDotlessFloat(stdlib) {
 assertWasm(55, TestDotlessFloat);
 
 
+function TestDotlessLocalFloat(stdlib) {
+  "use asm";
+  var fround = stdlib.Math.fround;
+  function caller() {
+    var foo = fround(55);
+    return +foo;
+  }
+  return {caller: caller};
+}
+
+assertWasm(55, TestDotlessLocalFloat);
+
+
 function TestFloatGlobals(stdlib) {
   "use asm";
   var fround = stdlib.Math.fround;