Remove obsolete instruction HOuterContext.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index 54798065761273791df8f034ed8ace3d4dee00b1..8a2711f3e28262abaa26778817b4b8fd436f58ec 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -3494,14 +3494,6 @@ void LCodeGen::DoContext(LContext* instr) {
 }
 
 
-void LCodeGen::DoOuterContext(LOuterContext* instr) {
-  Register context = ToRegister(instr->context());
-  Register result = ToRegister(instr->result());
-  __ lw(result,
-        MemOperand(context, Context::SlotOffset(Context::PREVIOUS_INDEX)));
-}
-
-
 void LCodeGen::DoDeclareGlobals(LDeclareGlobals* instr) {
   ASSERT(ToRegister(instr->context()).is(cp));
   __ li(scratch0(), instr->hydrogen()->pairs());