LibWeb: Provide file name to JavaScript interpreter

Author: https://github.com/boricj
Commit: 8dca96fb61
Pull-request: https://github.com/SerenityOS/serenity/pull/5547
Reviewed-by: https://github.com/alimpfard
Reviewed-by: https://github.com/linusg

Userland/Libraries/LibWeb/HTML/HTMLScriptElement.h

@@ -72,6 +72,7 @@ private:
     Function<void()> m_script_ready_callback;
 
     String m_script_source;
+    String m_script_filename;
 };
 
 }