Properly filter types using the initial map from HAllocate.

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index d0454fb059271912518ead496d6d95c01507e46c..c63090687b96a912975b39a69522a647d7d8a458 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -288,6 +288,14 @@ class SmallMapList V8_FINAL {
     Add(map, zone);
   }
 
+  void FilterForPossibleTransitions(Map* root_map) {
+    for (int i = list_.length() - 1; i >= 0; i--) {
+      if (at(i)->FindRootMap() != root_map) {
+        list_.RemoveElement(list_.at(i));
+      }
+    }
+  }
+
   void Add(Handle<Map> handle, Zone* zone) {
     list_.Add(handle.location(), zone);
   }
@@ -366,12 +374,6 @@ class Expression : public AstNode {
     UNREACHABLE();
     return NULL;
   }
-  Handle<Map> GetMonomorphicReceiverType() {
-    ASSERT(IsMonomorphic());
-    SmallMapList* types = GetReceiverTypes();
-    ASSERT(types != NULL && types->length() == 1);
-    return types->at(0);
-  }
   virtual KeyedAccessStoreMode GetStoreMode() {
     UNREACHABLE();
     return STANDARD_STORE;