Port faster callbacks invocation to x64.

src/ia32/macro-assembler-ia32.h

Index: src/ia32/macro-assembler-ia32.h
diff --git a/src/ia32/macro-assembler-ia32.h b/src/ia32/macro-assembler-ia32.h
index 02cfd4d9f326810c1df9e1fa767e3fd41e8c36a1..a17a2b4c1b9e6551c9e7b631c7fafe8133b8bd4e 100644
--- a/src/ia32/macro-assembler-ia32.h
+++ b/src/ia32/macro-assembler-ia32.h
@@ -393,12 +393,12 @@ class MacroAssembler: public Assembler {
   // Convenience function: Same as above, but takes the fid instead.
   void CallRuntime(Runtime::FunctionId id, int num_arguments);
 
-  // Convenience function: call an external reference.
-  void CallExternalReference(ExternalReference ref, int num_arguments);
-
   // Convenience function: Same as above, but takes the fid instead.
   Object* TryCallRuntime(Runtime::FunctionId id, int num_arguments);
 
+  // Convenience function: call an external reference.
+  void CallExternalReference(ExternalReference ref, int num_arguments);
+
   // Tail call of a runtime routine (jump).
   // Like JumpToExternalReference, but also takes care of passing the number
   // of parameters.
@@ -431,7 +431,7 @@ class MacroAssembler: public Assembler {
   void PushHandleScope(Register scratch);
 
   // Pops a handle scope using the specified scratch register and
-  // ensuring that saved register, it is not no_reg, is left unchanged.
+  // ensuring that saved register is left unchanged.
   void PopHandleScope(Register saved, Register scratch);
 
   // As PopHandleScope, but does not perform a GC.  Instead, returns a