[object] Add Script::IsUserJavaScript().

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index b6dc17a3243e3151f8e95d7cded225faf5517b34..fd6c8fc39518aeb7150a99905ff026f12aff6e0d 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -6687,6 +6687,8 @@ class Script: public Struct {
   bool GetPositionInfo(int position, PositionInfo* info,
                        OffsetFlag offset_flag) const;
 
+  bool IsUserJavaScript();
+
   // Wrappers for GetPositionInfo
   static int GetColumnNumber(Handle<Script> script, int code_offset);
   int GetColumnNumber(int code_pos) const;