Share optimized code for closures.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
===================================================================
--- src/arm/lithium-codegen-arm.cc	(revision 11812)
+++ src/arm/lithium-codegen-arm.cc	(working copy)
@@ -478,7 +478,10 @@
   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);
@@ -3089,7 +3092,7 @@
 
 void LCodeGen::DoThisFunction(LThisFunction* instr) {
   Register result = ToRegister(instr->result());
-  __ LoadHeapObject(result, instr->hydrogen()->closure());
+  __ ldr(result, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
 }