[crankshaft] Get rid of the StoreFrameContext instruction.

src/crankshaft/arm/lithium-arm.cc

Index: src/crankshaft/arm/lithium-arm.cc
diff --git a/src/crankshaft/arm/lithium-arm.cc b/src/crankshaft/arm/lithium-arm.cc
index cea70a23896f60b794c0736b59af0fec43582165..dce3c6b5d54bd48c214bd8d2ccf640991fcd2c78 100644
--- a/src/crankshaft/arm/lithium-arm.cc
+++ b/src/crankshaft/arm/lithium-arm.cc
@@ -2561,11 +2561,5 @@ LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   return AssignPointerMap(result);
 }
 
-
-LInstruction* LChunkBuilder::DoStoreFrameContext(HStoreFrameContext* instr) {
-  LOperand* context = UseRegisterAtStart(instr->context());
-  return new(zone()) LStoreFrameContext(context);
-}
-
 }  // namespace internal
 }  // namespace v8