[wasm][asm.js] Fix and enable several asm.js tests with the new parser.

test/mjsunit/wasm/asm-wasm-literals.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
+// Flags: --validate-asm --allow-natives-syntax --fast-validate-asm
 
 function RunAsmJsTest(asmfunc, expect) {
   var asm_source = asmfunc.toString();
   var nonasm_source = asm_source.replace(new RegExp("use asm"), "");
   var stdlib = {Math: Math};
 
   print("Testing " + asmfunc.name + " (js)...");
   var js_module = eval("(" + nonasm_source + ")")(stdlib);
   expect(js_module);
 
@@ skipping 237 matching lines @@
   // TODO(bradnelson): fails validation of F32 literals somehow.
 RunAsmJsTest(ManyF32a, function(module) {
   assertEquals(2.0999999917333043e-24, module.k1());
   assertEquals(2.099999868734112e-19, module.k2());
   assertEquals(2.099999997029825e-14, module.k3());
   assertEquals(2.099999951710174e-9, module.k4());
   assertEquals(0.0002099999983329326, module.k5());
   assertEquals(21.399999618530273, module.k6());
 });
 }