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

src/x64/lithium-codegen-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.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/base/bits.h"
 #include "src/code-stubs.h"
@@ skipping 1703 matching lines @@
 
 void LCodeGen::DoConstantS(LConstantS* instr) {
   __ Move(ToRegister(instr->result()), instr->value());
 }
 
 
 void LCodeGen::DoConstantD(LConstantD* instr) {
   DCHECK(instr->result()->IsDoubleRegister());
   XMMRegister res = ToDoubleRegister(instr->result());
   double v = instr->value();
-  uint64_t int_val = BitCast<uint64_t, double>(v);
+  uint64_t int_val = bit_cast<uint64_t, double>(v);
   // Use xor to produce +0.0 in a fast and compact way, but avoid to
   // do so if the constant is -0.0.
   if (int_val == 0) {
     __ xorps(res, res);
   } else {
     Register tmp = ToRegister(instr->temp());
     __ Set(tmp, int_val);
     __ movq(res, tmp);
   }
 }
@@ skipping 2605 matching lines @@
     // Sign extend key because it could be a 32 bit negative value
     // and the dehoisted address computation happens in 64 bits
     __ movsxlq(ToRegister(key), ToRegister(key));
   }
   if (instr->NeedsCanonicalization()) {
     Label have_value;
 
     __ ucomisd(value, value);
     __ j(parity_odd, &have_value, Label::kNear);  // NaN.
 
-    __ Set(kScratchRegister, BitCast<uint64_t>(
-        FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
+    __ Set(kScratchRegister,
+           bit_cast<uint64_t>(
+               FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
     __ movq(value, kScratchRegister);
 
     __ bind(&have_value);
   }
 
   Operand double_store_operand = BuildFastArrayOperand(
       instr->elements(),
       key,
       instr->hydrogen()->key()->representation(),
       FAST_DOUBLE_ELEMENTS,
@@ skipping 1489 matching lines @@
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64