use the full ascii set instead of a few chosen chars

Author: erik-krogh

javascript/ql/src/semmle/javascript/security/performance/ReDoSUtil.qll

@@ -915,7 +915,7 @@ private module SuffixConstruction {
    */
   pragma[noinline]
   private string relevant(RegExpRoot root) {
-    result = ["a", "9", " ", "|", "\n", "Z"] // must include all the strings from `hasSimpleRejectEdge`.
+    exists(ascii(result))
     or
     exists(InputSymbol s | belongsTo(s, root) | result = intersect(s, _))
   }