Remove broken _WIN64 checks.

src/compiler/x64/code-generator-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/compiler/code-generator.h"
 
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/gap-resolver.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties-inl.h"
 #include "src/scopes.h"
 #include "src/x64/assembler-x64.h"
 #include "src/x64/macro-assembler-x64.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
-#ifndef _WIN64
-
 #define __ masm()->
 
 
 // TODO(turbofan): Cleanup these hacks.
 enum Immediate64Type { kImm64Value, kImm64Handle, kImm64Reference };
 
 
 struct Immediate64 {
   uint64_t value;
   Handle<Object> handle;
@@ skipping 960 matching lines @@
                                             int end_pc) {
   if (start_pc + 1 != end_pc) {
     return false;
   }
   return *(code->instruction_start() + start_pc) ==
          v8::internal::Assembler::kNopByte;
 }
 
 #endif
 
-#endif
-}
-}
-}  // namespace v8::internal::compiler
+}  // namespace internal
+}  // namespace compiler
+}  // namespace v8