Fix invalid SMI test in x64 ToNumberStub::Generate().

src/x64/code-stubs-x64.cc

 // Copyright 2013 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 281 matching lines @@
     __ CallExternalReference(miss, descriptor->register_param_count_);
   }
 
   __ Ret();
 }
 
 
 void ToNumberStub::Generate(MacroAssembler* masm) {
   // The ToNumber stub takes one argument in rax.
   Label check_heap_number, call_builtin;
-  __ SmiTest(rax);
-  __ j(not_zero, &check_heap_number, Label::kNear);
+  __ JumpIfNotSmi(rax, &check_heap_number, Label::kNear);
   __ Ret();
 
   __ bind(&check_heap_number);
   __ CompareRoot(FieldOperand(rax, HeapObject::kMapOffset),
                  Heap::kHeapNumberMapRootIndex);
   __ j(not_equal, &call_builtin, Label::kNear);
   __ Ret();
 
   __ bind(&call_builtin);
   __ pop(rcx);  // Pop return address.
@@ skipping 6513 matching lines @@
   __ bind(&fast_elements_case);
   GenerateCase(masm, FAST_ELEMENTS);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64