Remove all harmony runtime flags which shipped in M51

test/mjsunit/es6/string-match.js

Index: test/mjsunit/es6/string-match.js
diff --git a/test/mjsunit/harmony/string-match.js b/test/mjsunit/es6/string-match.js
similarity index 94%
rename from test/mjsunit/harmony/string-match.js
rename to test/mjsunit/es6/string-match.js
index 25a3ca2fd1b691c6ceb52f86c0617fc42c182992..2c7affe4549e62d7c1b8cb098084048482ca82f1 100644
--- a/test/mjsunit/harmony/string-match.js
+++ b/test/mjsunit/es6/string-match.js
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-regexp-subclass
-
 var pattern = {};
 pattern[Symbol.match] = function(string) {
   return string.length;