Remove obsolete instruction HOuterContext.

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index d14b11f0ef8d035e5425c0b890ea53208ac1b989..c61c8a1a27e64a3e6d0e879ab8b267e5271f7034 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1045,12 +1045,6 @@ LInstruction* LChunkBuilder::DoContext(HContext* instr) {
 }
 
 
-LInstruction* LChunkBuilder::DoOuterContext(HOuterContext* instr) {
-  LOperand* context = UseRegisterAtStart(instr->value());
-  return DefineAsRegister(new(zone()) LOuterContext(context));
-}
-
-
 LInstruction* LChunkBuilder::DoDeclareGlobals(HDeclareGlobals* instr) {
   LOperand* context = UseFixed(instr->context(), cp);
   return MarkAsCall(new(zone()) LDeclareGlobals(context), instr);