MIPS: Share optimized code for closures.

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 67dbe69def967f89729e7ba435a5875b9a93ad63..2a022b5aa078938f486ce39c1b11acad9a02a3d5 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -446,7 +446,10 @@ void LCodeGen::WriteTranslation(LEnvironment* environment,
   int height = translation_size - environment->parameter_count();
 
   WriteTranslation(environment->outer(), translation);
-  int closure_id = DefineDeoptimizationLiteral(environment->closure());
+  int closure_id = *info()->closure() != *environment->closure()
+      ? DefineDeoptimizationLiteral(environment->closure())
+      : Translation::kSelfLiteralId;
+
   switch (environment->frame_type()) {
     case JS_FUNCTION:
       translation->BeginJSFrame(environment->ast_id(), closure_id, height);
@@ -2847,7 +2850,7 @@ void LCodeGen::DoDrop(LDrop* instr) {
 
 void LCodeGen::DoThisFunction(LThisFunction* instr) {
   Register result = ToRegister(instr->result());
-  __ LoadHeapObject(result, instr->hydrogen()->closure());
+  __ lw(result, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
 }