Port faster callbacks invocation to x64.

src/x64/assembler-x64.cc

 // 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 1478 matching lines @@
   }
   EnsureSpace ensure_space(this);
   last_pc_ = pc_;
   emit_rex_64(dst);
   emit(0xB8 | dst.low_bits());
   emitq(value, rmode);
 }
 
 
 void Assembler::movq(Register dst, ExternalReference ref) {
-  EnsureSpace ensure_space(this);
-  last_pc_ = pc_;
-  emit_rex_64(dst);
-  emit(0xB8 | dst.low_bits());
-  emitq(reinterpret_cast<uintptr_t>(ref.address()),
-        RelocInfo::EXTERNAL_REFERENCE);
+  int64_t value = reinterpret_cast<int64_t>(ref.address());
+  movq(dst, value, RelocInfo::EXTERNAL_REFERENCE);
 }
 
 
 void Assembler::movq(const Operand& dst, Immediate value) {
   EnsureSpace ensure_space(this);
   last_pc_ = pc_;
   emit_rex_64(dst);
   emit(0xC7);
   emit_operand(0, dst);
   emit(value);
@@ skipping 1439 matching lines @@
   // specially coded on x64 means that it is a relative 32 bit address, as used
   // by branch instructions.
   return (1 << rmode_) & kApplyMask;
 }
 
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64