Function.prototype.toString works on symbol-named built-ins

test/built-ins/Function/prototype/toString/symbol-named-builtins.js

+// Copyright (C) 2018 Michael Ficarra. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-function.prototype.tostring
+description: Function.prototype.toString on symbol-named built-ins
+includes: [nativeFunctionMatcher.js]
+---*/
+
+assertNativeFunction(RegExp.prototype[Symbol.match]);
+assertNativeFunction(Object.getOwnPropertyDescriptor(RegExp, Symbol.species).get);