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

src/ia32/lithium-codegen-ia32.h

Index: src/ia32/lithium-codegen-ia32.h
diff --git a/src/ia32/lithium-codegen-ia32.h b/src/ia32/lithium-codegen-ia32.h
index 32ea6bf17e2dae2211b6b397dd763bef83c762fe..256fa81d41533012b15ddcfff72138f6c5ed1cb0 100644
--- a/src/ia32/lithium-codegen-ia32.h
+++ b/src/ia32/lithium-codegen-ia32.h
@@ -101,6 +101,7 @@ class LCodeGen: public LCodeGenBase {
   void DoDeferredTaggedToI(LTaggedToI* instr, Label* done);
   void DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr);
   void DoDeferredStackCheck(LStackCheck* instr);
+  void DoDeferredMaybeGrowElements(LMaybeGrowElements* instr);
   void DoDeferredStringCharCodeAt(LStringCharCodeAt* instr);
   void DoDeferredStringCharFromCode(LStringCharFromCode* instr);
   void DoDeferredAllocate(LAllocate* instr);