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

test/mjsunit/regress-crbug-528379.js

Index: test/mjsunit/regress-crbug-528379.js
diff --git a/test/mjsunit/regress-crbug-528379.js b/test/mjsunit/regress-crbug-528379.js
deleted file mode 100644
index f335f6a104bababf0be733d4c22adb5d694fac8a..0000000000000000000000000000000000000000
--- a/test/mjsunit/regress-crbug-528379.js
+++ /dev/null
@@ -1,8 +0,0 @@
-// Copyright 2015 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: --enable-slow-asserts
-
-Error.prepareStackTrace = function(e, frames) { return frames; }
-assertThrows(function() { new Error().stack[0].getMethodName.call({}); });