[wasm] [asm.js] Fix various asm.js issues.

test/mjsunit/wasm/asm-wasm-f32.js

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --validate-asm --allow-natives-syntax
 
 function WrapInAsmModule(func) {
   function MODULE_NAME(stdlib) {
     "use asm";
     var fround = stdlib.Math.fround;
@@ skipping 141 matching lines @@
 
 function f32_gteq(a, b) {
   a = fround(a);
   b = fround(b);
   if (fround(a) >= fround(b)) {
     return 1;
   }
   return 0;
 }
 
+function f32_neg(a) {
+  a = fround(a);
+  return fround(-a);
+}
+
 
 var inputs = [
   0, 1, 2, 3, 4,
   NaN,
   Infinity,
   -Infinity,
   10, 20, 30, 31, 32, 33, 100, 2000,
   30000, 400000, 5000000,
   100000000, 2000000000,
   2147483646,
@@ skipping 32 matching lines @@
 // TODO(bradnelson) f32_sqrt,
 // TODO(bradnelson) f32_abs,
 // TODO(bradnelson) f32_min is wrong for -0
 // TODO(bradnelson) f32_max is wrong for -0
   f32_eq,
   f32_ne,
   f32_lt,
   f32_lteq,
   f32_gt,
   f32_gteq,
+  f32_neg,
 ];
 
 (function () {
   for (func of funcs) {
     RunAsmJsTest(WrapInAsmModule(func), function (module) {
       if (func.length == 1) {
         for (a of inputs) {
           assertEquals(func(a), module.main(a));
           assertEquals(func(a / 11), module.main(a / 11));
           assertEquals(func(a / 430.9), module.main(a / 430.9));
           assertEquals(func(a / -31.1), module.main(a / -31.1));
         }
       } else {
         for (a of inputs) {
           for (b of inputs) {
             assertEquals(func(a, b), module.main(a, b));
             assertEquals(func(a / 11,  b), module.main(a / 11, b));
             assertEquals(func(a, b / 420.9), module.main(a, b / 420.9));
             assertEquals(func(a / -31.1, b), module.main(a / -31.1, b));
           }
         }
       }
     });
   }
 
 })();