Remove always-on --harmony-rest-parameters flag

test/mjsunit/harmony/regress/regress-4211.js

Index: test/mjsunit/harmony/regress/regress-4211.js
diff --git a/test/mjsunit/harmony/regress/regress-4211.js b/test/mjsunit/harmony/regress/regress-4211.js
deleted file mode 100644
index d83c1a71f99237ed01745f72e68c2feda57e5a15..0000000000000000000000000000000000000000
--- a/test/mjsunit/harmony/regress/regress-4211.js
+++ /dev/null
@@ -1,12 +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: --harmony-rest-parameters
-
-assertThrows("()=>{}()", SyntaxError);
-assertThrows("x=>{}()", SyntaxError);
-assertThrows("(...x)=>{}()", SyntaxError);
-assertThrows("(x)=>{}()", SyntaxError);
-assertThrows("(x,y)=>{}()", SyntaxError);
-assertThrows("(x,y,...z)=>{}()", SyntaxError);