[crankshaft] Get rid of the StoreFrameContext instruction.

src/crankshaft/x87/lithium-x87.cc

Index: src/crankshaft/x87/lithium-x87.cc
diff --git a/src/crankshaft/x87/lithium-x87.cc b/src/crankshaft/x87/lithium-x87.cc
index e98a9bca904b170fb7e7b9d13801cf7597965bb9..635916dc53396021ab0116dff9dc3dc63933a953 100644
--- a/src/crankshaft/x87/lithium-x87.cc
+++ b/src/crankshaft/x87/lithium-x87.cc
@@ -2618,13 +2618,6 @@ 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