Clean up handling of global cell stores in the optimizing compiler.

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
diff --git a/src/x64/lithium-x64.h b/src/x64/lithium-x64.h
index 280d2358c4c243942e42dbf65bc9dcae79353358..c6fcfeb81ea867f8d9a82b0888ff8cc429996bd0 100644
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -1231,16 +1231,17 @@ class LLoadGlobalGeneric: public LTemplateInstruction<1, 1, 0> {
 };
 
 
-class LStoreGlobalCell: public LTemplateInstruction<0, 1, 2> {
+class LStoreGlobalCell: public LTemplateInstruction<0, 1, 1> {
  public:
-  explicit LStoreGlobalCell(LOperand* value, LOperand* temp1, LOperand* temp2) {
+  explicit LStoreGlobalCell(LOperand* value, LOperand* temp) {
     inputs_[0] = value;
-    temps_[0] = temp1;
-    temps_[1] = temp2;
+    temps_[0] = temp;
   }
 
   DECLARE_CONCRETE_INSTRUCTION(StoreGlobalCell, "store-global-cell")
   DECLARE_HYDROGEN_ACCESSOR(StoreGlobalCell)
+
+  LOperand* value() { return inputs_[0]; }
 };