Allow inlining of named function expressions containing ThisFunction reference.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
===================================================================
--- src/hydrogen-instructions.h	(revision 9687)
+++ src/hydrogen-instructions.h	(working copy)
@@ -1347,7 +1347,7 @@
 
 class HThisFunction: public HTemplateInstruction<0> {
  public:
-  HThisFunction() {
+  explicit HThisFunction(Handle<JSFunction> closure) : closure_(closure) {
     set_representation(Representation::Tagged());
     SetFlag(kUseGVN);
   }
@@ -1356,10 +1356,18 @@
     return Representation::None();
   }
 
+  Handle<JSFunction> closure() const { return closure_; }
+
   DECLARE_CONCRETE_INSTRUCTION(ThisFunction)
 
  protected:
-  virtual bool DataEquals(HValue* other) { return true; }
+  virtual bool DataEquals(HValue* other) {
+    HThisFunction* b = HThisFunction::cast(other);
+    return *closure() == *b->closure();
+  }
+
+ private:
+  Handle<JSFunction> closure_;
 };