Revert of Remove SIMD.js from V8.

src/x64/code-stubs-x64.cc

 // Copyright 2013 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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-stubs.h"
 #include "src/api-arguments.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 848 matching lines @@
     __ j(equal, &heap_number, Label::kNear);
     if (cc != equal) {
       __ movp(rcx, FieldOperand(rax, HeapObject::kMapOffset));
       __ movzxbl(rcx, FieldOperand(rcx, Map::kInstanceTypeOffset));
       // Call runtime on identical objects.  Otherwise return equal.
       __ cmpb(rcx, Immediate(static_cast<uint8_t>(FIRST_JS_RECEIVER_TYPE)));
       __ j(above_equal, &runtime_call, Label::kFar);
       // Call runtime on identical symbols since we need to throw a TypeError.
       __ cmpb(rcx, Immediate(static_cast<uint8_t>(SYMBOL_TYPE)));
       __ j(equal, &runtime_call, Label::kFar);
+      // Call runtime on identical SIMD values since we must throw a TypeError.
+      __ cmpb(rcx, Immediate(static_cast<uint8_t>(SIMD128_VALUE_TYPE)));
+      __ j(equal, &runtime_call, Label::kFar);
     }
     __ Set(rax, EQUAL);
     __ ret(0);
 
     __ bind(&heap_number);
     // It is a heap number, so return  equal if it's not NaN.
     // For NaN, return 1 for every condition except greater and
     // greater-equal.  Return -1 for them, so the comparison yields
     // false for all conditions except not-equal.
     __ Set(rax, EQUAL);
@@ skipping 2435 matching lines @@
                            kStackUnwindSpace, nullptr, return_value_operand,
                            NULL);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64