Push safepoint registers in deferred number-to-i/u only on-demand.

src/x64/lithium-x64.h

 // 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 1874 matching lines @@
   explicit LNumberTagI(LOperand* value) {
     inputs_[0] = value;
   }
 
   LOperand* value() { return inputs_[0]; }
 
   DECLARE_CONCRETE_INSTRUCTION(NumberTagI, "number-tag-i")
 };
 
 
-class LNumberTagU V8_FINAL : public LTemplateInstruction<1, 1, 1> {
+class LNumberTagU V8_FINAL : public LTemplateInstruction<1, 1, 2> {
  public:
-  explicit LNumberTagU(LOperand* value, LOperand* temp) {
+  LNumberTagU(LOperand* value, LOperand* temp1, LOperand* temp2) {
     inputs_[0] = value;
-    temps_[0] = temp;
+    temps_[0] = temp1;
+    temps_[1] = temp2;
   }
 
   LOperand* value() { return inputs_[0]; }
-  LOperand* temp() { return temps_[0]; }
+  LOperand* temp1() { return temps_[0]; }
+  LOperand* temp2() { return temps_[1]; }
 
   DECLARE_CONCRETE_INSTRUCTION(NumberTagU, "number-tag-u")
 };
 
 
 class LNumberTagD V8_FINAL : public LTemplateInstruction<1, 1, 1> {
  public:
   explicit LNumberTagD(LOperand* value, LOperand* temp) {
     inputs_[0] = value;
     temps_[0] = temp;
@@ skipping 751 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };
 
 #undef DECLARE_HYDROGEN_ACCESSOR
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::int
 
 #endif  // V8_X64_LITHIUM_X64_H_