Object.prototype.toString: Improve revoked Proxy coverage

test/built-ins/Object/prototype/toString/proxy-revoked-during-get-call.js

@@ -0,0 +1,50 @@
+// Copyright (C) 2020 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  If Proxy is revoked during Get call, a string is returned.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  4. Let isArray be ? IsArray(O).
+  [...]
+  14. Else, let builtinTag be "Object".
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+
+  IsArray ( argument )
+
+  [...]
+  3. If argument.[[ProxyHandler]] is null, throw a TypeError exception.
+    a. If argument.[[ProxyHandler]] is null, throw a TypeError exception.
+    b. Let target be argument.[[ProxyTarget]].
+    c. Return ? IsArray(target).
+features: [Proxy]
+---*/
+
+var handle1 = Proxy.revocable([], {
+  get: function() {
+    handle1.revoke();
+  },
+});
+
+assert.sameValue(
+  Object.prototype.toString.call(handle1.proxy),
+  "[object Array]"
+);
+
+
+var handle2 = Proxy.revocable({}, {
+  get: function() {
+    handle2.revoke();
+  },
+});
+
+var handle2Proxy = new Proxy(handle2.proxy, {});
+assert.sameValue(
+  Object.prototype.toString.call(handle2Proxy),
+  "[object Object]"
+);