Delete mjsunit/string-oom-slow-* tests.

test/mjsunit/string-oom-slow-json-stringify.js

Index: test/mjsunit/string-oom-slow-json-stringify.js
diff --git a/test/mjsunit/string-oom-slow-json-stringify.js b/test/mjsunit/string-oom-slow-json-stringify.js
deleted file mode 100644
index 2f9965599a65598ebcf98c661a1d292ebbd937e0..0000000000000000000000000000000000000000
--- a/test/mjsunit/string-oom-slow-json-stringify.js
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2014 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.
-
-var a = 'a';
-for (var i = 0; i < 20; i++) a += a;
-for (var i = 0; i < 8; i++) a = [a, a];
-
-function stringify() {
-  JSON.stringify(a);
-}
-
-assertThrows(stringify, RangeError);