Remove all harmony runtime flags which shipped in M51

test/mjsunit/harmony/unicode-regexp-unanchored-advance.js

Index: test/mjsunit/harmony/unicode-regexp-unanchored-advance.js
diff --git a/test/mjsunit/harmony/unicode-regexp-unanchored-advance.js b/test/mjsunit/harmony/unicode-regexp-unanchored-advance.js
deleted file mode 100644
index 97960e1cd30c4d7cd5b7141640b9defa06c40170..0000000000000000000000000000000000000000
--- a/test/mjsunit/harmony/unicode-regexp-unanchored-advance.js
+++ /dev/null
@@ -1,8 +0,0 @@
-// Copyright 2013 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --harmony-unicode-regexps
-
-var s = "a".repeat(1E7) + "\u1234";
-assertEquals(["\u1234", "\u1234"], /(\u1234)/u.exec(s));