[x64] Use vmovapd and vmovsd when AVX is enabled.

test/cctest/test-code-stubs-x64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Rrdistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Rrdistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Rrdistributions 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 70 matching lines @@
   for (; reg_num < config->num_allocatable_general_registers(); ++reg_num) {
     Register reg =
         Register::from_code(config->GetAllocatableGeneralCode(reg_num));
     if (!reg.is(rsp) && !reg.is(rbp) && !reg.is(destination_reg)) {
       __ pushq(reg);
     }
   }
 
   // Put the double argument into the designated double argument slot.
   __ subq(rsp, Immediate(kDoubleSize));
-  __ movsd(MemOperand(rsp, 0), xmm0);
+  __ Movsd(MemOperand(rsp, 0), xmm0);
 
   // Call through to the actual stub
   __ Call(start, RelocInfo::EXTERNAL_REFERENCE);
 
   __ addq(rsp, Immediate(kDoubleSize));
 
   // Make sure no registers have been unexpectedly clobbered
   for (--reg_num; reg_num >= 0; --reg_num) {
     Register reg =
         Register::from_code(config->GetAllocatableGeneralCode(reg_num));
@@ skipping 46 matching lines @@
 
   for (size_t s = 0; s < sizeof(source_registers) / sizeof(Register); s++) {
     for (size_t d = 0; d < sizeof(dest_registers) / sizeof(Register); d++) {
       RunAllTruncationTests(
           MakeConvertDToIFuncTrampoline(isolate,
                                         source_registers[s],
                                         dest_registers[d]));
     }
   }
 }