readline: fix permanent deoptimizations

PR-URL: #12456
Reviewed-By: Benjamin Gruenbaum <[email protected]>
Reviewed-By: James M Snell <[email protected]>

Author: mscdex

lib/readline.js

@@ -449,8 +449,8 @@ Interface.prototype._tabComplete = function(lastKeypressWasTab) {
       }
 
       // If there is a common prefix to all matches, then apply that portion.
-      const f = completions.filter(function(e) { if (e) return e; });
-      const prefix = commonPrefix(f);
+      var f = completions.filter(function(e) { if (e) return e; });
+      var prefix = commonPrefix(f);
       if (prefix.length > completeOn.length) {
         self._insertString(prefix.slice(completeOn.length));
       }