Expose SIMD.Float32x4 type to Javascript.

test/simdjs/harness-adapt.js

 // Copyright 2015 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.
 
 (function() {
 
 "use strict";
 
 var _oldLoad = load;
 
 // Filter load paths in the ecmascript_simd tests that
 // assume the test is run with a current working directory
 // set to the directory containing the test.
 load = function(filename) {
   // Decide if this is the compliance test or the benchmarks.
   if (filename === 'ecmascript_simd.js' ||
       filename === 'ecmascript_simd_tests.js') {
     _oldLoad('test/simdjs/data/src/' + filename);
   } else {
     _oldLoad('test/simdjs/data/src/benchmarks/' + filename);
   }
 };
 
 // TODO(bbudge): Drop when polyfill is not needed.
 load('ecmascript_simd.js');
 
 load('base.js');
 
 })();
+
+// ecmascript_simd_tests logs errors to the console.
+var console = {
+  log: function(x) { print(x); },
+};