Add Proxy.revocable built-in test

test/built-ins/Proxy/revocable/builtin.js

@@ -0,0 +1,18 @@
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-proxy.revocable
+description: >
+  Requirements for built-in functions, defined in introduction of chapter 17,
+  are satisfied.
+includes: [isConstructor.js]
+features: [Proxy, Reflect.construct]
+---*/
+
+assert(Object.isExtensible(Proxy.revocable));
+assert.sameValue(typeof Proxy.revocable, 'function');
+assert.sameValue(Object.prototype.toString.call(Proxy.revocable), '[object Function]');
+assert.sameValue(Object.getPrototypeOf(Proxy.revocable), Function.prototype);
+
+assert.sameValue(Proxy.revocable.hasOwnProperty('prototype'), false);
+assert.sameValue(isConstructor(Proxy.revocable), false);