Use Unique<Cell> and Unique<PropertyCell> in LoadGlobalCell and StoreGlobalCell.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index 6f82e1bd75d77d9362318cec51cb23be206f7cd1..a9c4a4ca10826e244e33ef279607cc68221e7178 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -2805,7 +2805,7 @@ void LCodeGen::DoReturn(LReturn* instr) {
 
 void LCodeGen::DoLoadGlobalCell(LLoadGlobalCell* instr) {
   Register result = ToRegister(instr->result());
-  __ li(at, Operand(Handle<Object>(instr->hydrogen()->cell())));
+  __ li(at, Operand(Handle<Object>(instr->hydrogen()->cell().handle())));
   __ lw(result, FieldMemOperand(at, Cell::kValueOffset));
   if (instr->hydrogen()->RequiresHoleCheck()) {
     __ LoadRoot(at, Heap::kTheHoleValueRootIndex);
@@ -2831,7 +2831,7 @@ void LCodeGen::DoStoreGlobalCell(LStoreGlobalCell* instr) {
   Register cell = scratch0();
 
   // Load the cell.
-  __ li(cell, Operand(instr->hydrogen()->cell()));
+  __ li(cell, Operand(instr->hydrogen()->cell().handle()));
 
   // If the cell we are storing to contains the hole it could have
   // been deleted from the property dictionary. In that case, we need