Replace our home-grown BitCast with bit_cast from Chrome/Google3.

test/cctest/test-macro-assembler-mips.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 131 matching lines @@
 
   v8::Local<v8::Script> script = v8::Script::Compile(v8_str(code));
   v8::Local<v8::Object> result = v8::Local<v8::Object>::Cast(script->Run());
   // Have to populate the handle manually, as it's not Cast-able.
   i::Handle<i::JSObject> o =
       v8::Utils::OpenHandle<v8::Object, i::JSObject>(result);
   i::Handle<i::JSArray> array1(reinterpret_cast<i::JSArray*>(*o));
   i::FixedDoubleArray* a = i::FixedDoubleArray::cast(array1->elements());
   double value = a->get_scalar(0);
   CHECK(std::isnan(value) &&
-        i::BitCast<uint64_t>(value) ==
-        i::BitCast<uint64_t>(
-            i::FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
+        i::bit_cast<uint64_t>(value) ==
+            i::bit_cast<uint64_t>(
+                i::FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
 }
 
 
 TEST(NaN0) {
   TestNaN(
           "var result;"
           "for (var i = 0; i < 2; i++) {"
           "  result = new Array(Number.NaN, Number.POSITIVE_INFINITY);"
           "}"
           "result;");
 }
 
 
 TEST(NaN1) {
   TestNaN(
           "var result;"
           "for (var i = 0; i < 2; i++) {"
           "  result = [NaN];"
           "}"
           "result;");
 }
 
 
 #undef __