Introduce LoadSharedFunctionInfoSpecialField for x64 port.

src/x64/builtins-x64.cc

 // Copyright 2012 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 945 matching lines @@
     __ GetBuiltinEntry(rdx, Builtins::CALL_NON_FUNCTION);
     __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
             RelocInfo::CODE_TARGET);
     __ bind(&function);
   }
 
   // 5b. Get the code to call from the function and check that the number of
   //     expected arguments matches what we're providing.  If so, jump
   //     (tail-call) to the code in register edx without checking arguments.
   __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
-  __ movsxlq(rbx,
-             FieldOperand(rdx,
-                          SharedFunctionInfo::kFormalParameterCountOffset));
+  __ LoadSharedFunctionInfoSpecialField(rbx, rdx,
+      SharedFunctionInfo::kFormalParameterCountOffset);
   __ movp(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
   __ cmpp(rax, rbx);
   __ j(not_equal,
        masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
        RelocInfo::CODE_TARGET);
 
   ParameterCount expected(0);
   __ InvokeCode(rdx, expected, expected, JUMP_FUNCTION, NullCallWrapper());
 }
 
@@ skipping 515 matching lines @@
   __ bind(&ok);
   __ ret(0);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64