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

src/type-info.h

Index: src/type-info.h
diff --git a/src/type-info.h b/src/type-info.h
index cb3e75d8abe7271fa546d6f03f26171ef9abf962..3fc33a8c59a18bd7ae7ba837fe37bdd850f565db 100644
--- a/src/type-info.h
+++ b/src/type-info.h
@@ -262,15 +262,17 @@ class TypeFeedbackOracle BASE_EMBEDDED {
 
   bool IsMonomorphic(int pos) { return GetElement(map_, pos)->IsMap(); }
 
-  ZoneMapList* CollectReceiverTypes(int position,
+  ZoneMapList* CollectReceiverTypes(AstId id,
                                     Handle<String> name,
                                     Code::Flags flags);
 
   void PopulateMap(Handle<Code> code);
 
-  void CollectPositions(Code* code,
-                        List<int>* code_positions,
-                        List<int>* source_positions);
+  void CollectIds(Code* code,
+                  List<int>* code_positions,
+                  List<AstId>* ast_ids);
+
+  void SetInfo(AstId id, Handle<Object> info);
 
   Handle<JSObject> map_;