Patch to enhance the source code line information for profiler.

src/ia32/lithium-ia32.h

Index: src/ia32/lithium-ia32.h
===================================================================
--- src/ia32/lithium-ia32.h	(revision 15925)
+++ src/ia32/lithium-ia32.h	(working copy)
@@ -212,7 +212,8 @@
   LInstruction()
       : environment_(NULL),
         hydrogen_value_(NULL),
-        is_call_(false) { }
+        is_call_(false),
+        position_(RelocInfo::kNoPosition) { }
   virtual ~LInstruction() { }
 
   virtual void CompileToNative(LCodeGen* generator) = 0;
@@ -251,6 +252,8 @@
   LPointerMap* pointer_map() const { return pointer_map_.get(); }
   bool HasPointerMap() const { return pointer_map_.is_set(); }
 
+  void set_position(int pos) { position_ = pos; }
+  int position() { return position_; }
 
   void set_hydrogen_value(HValue* value) { hydrogen_value_ = value; }
   HValue* hydrogen_value() const { return hydrogen_value_; }
@@ -300,6 +303,7 @@
   SetOncePointer<LPointerMap> pointer_map_;
   HValue* hydrogen_value_;
   bool is_call_;
+  int position_;

[danno, 2013/07/29 12:29:01]

Please turn this into a bit field with is_call using the BitField class so that
it doesn't use an extra word in the LInstruction class. 

 };