PPC: New hydrogen instruction to reduce cost of growing an array on keyed stores.

src/ppc/lithium-ppc.cc

Index: src/ppc/lithium-ppc.cc
diff --git a/src/ppc/lithium-ppc.cc b/src/ppc/lithium-ppc.cc
index db6cfb20515ac9be56ccf8ac86247a4f543c0ccc..1c45eb7f4d3e4bcb780a09cec8604834967b8f88 100644
--- a/src/ppc/lithium-ppc.cc
+++ b/src/ppc/lithium-ppc.cc
@@ -2322,6 +2322,21 @@ LInstruction* LChunkBuilder::DoTrapAllocationMemento(
 }
 
 
+LInstruction* LChunkBuilder::DoMaybeGrowElements(HMaybeGrowElements* instr) {
+  info()->MarkAsDeferredCalling();
+  LOperand* context = UseFixed(instr->context(), cp);
+  LOperand* object = Use(instr->object());
+  LOperand* elements = Use(instr->elements());
+  LOperand* key = UseRegisterOrConstant(instr->key());
+  LOperand* current_capacity = UseRegisterOrConstant(instr->current_capacity());
+
+  LMaybeGrowElements* result = new (zone())
+      LMaybeGrowElements(context, object, elements, key, current_capacity);
+  DefineFixed(result, r3);
+  return AssignPointerMap(AssignEnvironment(result));
+}
+
+
 LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
   bool is_in_object = instr->access().IsInobject();
   bool needs_write_barrier = instr->NeedsWriteBarrier();