[simd] Disable Simd Scalar lowering for x64, enable tests for all other architectures.

src/x64/assembler-x64-inl.h

 // Copyright 2012 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.
 
 #ifndef V8_X64_ASSEMBLER_X64_INL_H_
 #define V8_X64_ASSEMBLER_X64_INL_H_
 
 #include "src/x64/assembler-x64.h"
 
 #include "src/base/cpu.h"
 #include "src/debug/debug.h"
 #include "src/v8memory.h"
 
 namespace v8 {
 namespace internal {
 
 bool CpuFeatures::SupportsCrankshaft() { return true; }
 
-bool CpuFeatures::SupportsSimd128() { return false; }
+bool CpuFeatures::SupportsSimd128() { return true; }
 
 // -----------------------------------------------------------------------------
 // Implementation of Assembler
 
 
 static const byte kCallOpcode = 0xE8;
 // The length of pushq(rbp), movp(rbp, rsp), Push(rsi) and Push(rdi).
 static const int kNoCodeAgeSequenceLength = kPointerSize == kInt64Size ? 6 : 17;
 
 
@@ skipping 566 matching lines @@
 void Operand::set_disp64(int64_t disp) {
   DCHECK_EQ(1, len_);
   int64_t* p = reinterpret_cast<int64_t*>(&buf_[len_]);
   *p = disp;
   len_ += sizeof(disp);
 }
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_X64_ASSEMBLER_X64_INL_H_