Make GeneratedFileMarker an instance of JavadocElement

Author: atorralba

java/ql/lib/semmle/code/java/GeneratedFiles.qll

@@ -51,9 +51,9 @@ library class MarkerCommentGeneratedFile extends GeneratedFile {
 /**
  * A marker comment that indicates that it is in a generated file.
  */
-private class GeneratedFileMarker extends Top {
+private class GeneratedFileMarker extends Top instanceof JavadocElement {
   GeneratedFileMarker() {
-    exists(string msg | msg = this.(JavadocElement).getText() |
+    exists(string msg | msg = this.getText() |
       msg.regexpMatch("(?i).*\\bGenerated By\\b.*\\bDo not edit\\b.*") or
       msg.regexpMatch("(?i).*\\bThis (file|class|interface|art[ei]fact) (was|is|(has been)) (?:auto[ -]?)?gener(e?)ated.*") or
       msg.regexpMatch("(?i).*\\bAny modifications to this file will be lost\\b.*") or