Add AsyncGeneratorFunction test

test/built-ins/AsyncGeneratorFunction/proto-from-ctor-realm-prototype.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-createdynamicfunction
+description: >
+  While default [[Prototype]] value derives from realm of the newTarget,
+  "prototype" object inherits from %Object.prototype% of constructor's realm.
+info: |
+  AsyncGeneratorFunction ( p1, p2, … , pn, body )
+
+  [...]
+  3. Return ? CreateDynamicFunction(C, NewTarget, asyncGenerator, args).
+
+  CreateDynamicFunction ( constructor, newTarget, kind, args )
+
+  [...]
+  18. Let proto be ? GetPrototypeFromConstructor(newTarget, fallbackProto).
+  19. Let realmF be the current Realm Record.
+  20. Let scope be realmF.[[GlobalEnv]].
+  21. Let F be ! OrdinaryFunctionCreate(proto, parameters, body, non-lexical-this, scope).
+  [...]
+  24. Else if kind is asyncGenerator, then
+    a. Let prototype be OrdinaryObjectCreate(%AsyncGenerator.prototype%).
+    b. Perform DefinePropertyOrThrow(F, "prototype", PropertyDescriptor { [[Value]]:
+    prototype, [[Writable]]: true, [[Enumerable]]: false, [[Configurable]]: false }).
+  [...]
+  30. Return F.
+features: [async-iteration, cross-realm, Reflect]
+---*/
+
+var realmA = $262.createRealm().global;
+realmA.calls = 0;
+var aAsyncGeneratorFunction = realmA.eval("(async function* () {})").constructor;
+var aAsyncGeneratorPrototype = Object.getPrototypeOf(
+  realmA.eval("(async function* () {})").prototype
+);
+
+var realmB = $262.createRealm().global;
+var bAsyncGeneratorFunction = realmB.eval("(async function* () {})").constructor;
+var newTarget = new realmB.Function();
+newTarget.prototype = null;
+
+var fn = Reflect.construct(aAsyncGeneratorFunction, ["calls += 1;"], newTarget);
+assert.sameValue(Object.getPrototypeOf(fn), bAsyncGeneratorFunction.prototype);
+assert.sameValue(Object.getPrototypeOf(fn.prototype), aAsyncGeneratorPrototype);
+
+var gen = fn();
+assert(gen instanceof realmA.Object);
+gen.next();
+assert.sameValue(realmA.calls, 1);