Port the initial fast code generator to x64. For the constant true in...

src/fast-codegen.h

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions 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 10 matching lines @@
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_FAST_CODEGEN_H_
 #define V8_FAST_CODEGEN_H_
 
-#ifdef V8_TARGET_ARCH_IA32
+#ifndef V8_TARGET_ARCH_ARM
 
 #include "v8.h"
 
 #include "ast.h"
 
 namespace v8 {
 namespace internal {
 
 class FastCodeGenerator: public AstVisitor {
  public:
@@ skipping 14 matching lines @@
 #undef DECLARE_VISIT
 
   MacroAssembler* masm_;
   FunctionLiteral* function_;
 
   DISALLOW_COPY_AND_ASSIGN(FastCodeGenerator);
 };
 
 } }  // namespace v8::internal
 
-#endif  // V8_TARGET_ARCH_IA32
+#endif  // !defined(V8_TARGET_ARCH_ARM)
 #endif  // V8_FAST_CODEGEN_H_