Add ES2015 RegExp full subclassing semantics behind a flag

src/js/harmony-regexp-exec.js

Index: src/js/harmony-regexp-exec.js
diff --git a/src/js/harmony-regexp-exec.js b/src/js/harmony-regexp-exec.js
new file mode 100644
index 0000000000000000000000000000000000000000..e2eece98aa58be068543beef048b3d47f053f8ff
--- /dev/null
+++ b/src/js/harmony-regexp-exec.js
@@ -0,0 +1,37 @@
+// Copyright 2012 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.
+
+(function(global, utils) {
+
+%CheckIsBootstrapping();
+
+// -------------------------------------------------------------------
+// Imports
+
+var GlobalRegExp = global.RegExp;
+var RegExpSubclassExecJS = utils.ImportNow("RegExpSubclassExecJS");
+var RegExpSubclassMatch = utils.ImportNow("RegExpSubclassMatch");
+var RegExpSubclassReplace = utils.ImportNow("RegExpSubclassReplace");
+var RegExpSubclassSearch = utils.ImportNow("RegExpSubclassSearch");
+var RegExpSubclassSplit = utils.ImportNow("RegExpSubclassSplit");
+var RegExpSubclassTest = utils.ImportNow("RegExpSubclassTest");
+var matchSymbol = utils.ImportNow("match_symbol");
+var replaceSymbol = utils.ImportNow("replace_symbol");
+var searchSymbol = utils.ImportNow("search_symbol");
+var splitSymbol = utils.ImportNow("split_symbol");
+
+utils.OverrideFunction(GlobalRegExp.prototype, "exec",
+                       RegExpSubclassExecJS, true);
+utils.OverrideFunction(GlobalRegExp.prototype, matchSymbol,
+                       RegExpSubclassMatch, true);
+utils.OverrideFunction(GlobalRegExp.prototype, replaceSymbol,
+                       RegExpSubclassReplace, true);
+utils.OverrideFunction(GlobalRegExp.prototype, searchSymbol,
+                       RegExpSubclassSearch, true);
+utils.OverrideFunction(GlobalRegExp.prototype, splitSymbol,
+                       RegExpSubclassSplit, true);
+utils.OverrideFunction(GlobalRegExp.prototype, "test",
+                       RegExpSubclassTest, true);
+
+})