RFC: Switch to ast ids (instead of positions) for type feedback.

src/ia32/lithium-ia32.h

Index: src/ia32/lithium-ia32.h
diff --git a/src/ia32/lithium-ia32.h b/src/ia32/lithium-ia32.h
index c97859cfc907a56ccad168f58117581217744b4c..c140c9cee5de4b07e1c6d7fb3142cd5190489c29 100644
--- a/src/ia32/lithium-ia32.h
+++ b/src/ia32/lithium-ia32.h
@@ -1864,7 +1864,7 @@ class LEnvironment: public ZoneObject {
  private:
   Handle<JSFunction> closure_;
   int arguments_stack_height_;
-  int deoptimization_index_;
+  AstId deoptimization_index_;
   int translation_index_;
   int ast_id_;
   int parameter_count_;
@@ -1954,7 +1954,7 @@ class LChunkBuilder BASE_EMBEDDED {
         allocator_(allocator),
         position_(RelocInfo::kNoPosition),
         instructions_pending_deoptimization_environment_(NULL),
-        pending_deoptimization_ast_id_(AstNode::kNoNumber) { }
+        pending_deoptimization_ast_id_(kNoAstId) { }
 
   // Build the sequence for the graph.
   LChunk* Build();
@@ -2068,7 +2068,7 @@ class LChunkBuilder BASE_EMBEDDED {
   LAllocator* allocator_;
   int position_;
   LInstruction* instructions_pending_deoptimization_environment_;
-  int pending_deoptimization_ast_id_;
+  AstId pending_deoptimization_ast_id_;
 
   DISALLOW_COPY_AND_ASSIGN(LChunkBuilder);
 };