[crankshaft] Get rid of the StoreFrameContext instruction.

src/crankshaft/mips/lithium-mips.cc

Index: src/crankshaft/mips/lithium-mips.cc
diff --git a/src/crankshaft/mips/lithium-mips.cc b/src/crankshaft/mips/lithium-mips.cc
index 5f7bbdd7c9c37b4a48305f5795ddde05ea3337f2..577dc68585d271fd2e18fefe1a5975e9a808fd1b 100644
--- a/src/crankshaft/mips/lithium-mips.cc
+++ b/src/crankshaft/mips/lithium-mips.cc
@@ -2508,13 +2508,6 @@ 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