Cleanup: Move mjsunit/regress-*.js into mjsunit/regress/.

test/mjsunit/regress-crbug-663410.js

Index: test/mjsunit/regress-crbug-663410.js
diff --git a/test/mjsunit/regress-crbug-663410.js b/test/mjsunit/regress-crbug-663410.js
deleted file mode 100644
index 5bef089f11722cc2e2f97ddab9d0773cb293172d..0000000000000000000000000000000000000000
--- a/test/mjsunit/regress-crbug-663410.js
+++ /dev/null
@@ -1,8 +0,0 @@
-// Copyright 2016 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 alert(x) {};
-assertThrows(
-  Function("a=`","`,xss=1){alert(xss)")
-);