[ESNext] Implement DynamicImportCall

test/mjsunit/harmony/modules-import-2.js

+// Copyright 2017 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: --allow-natives-syntax --harmony-dynamic-import
+
+var life;
+var msg;
+import('modules-skip-1.js').then(namespace => life = namespace.life());
+import('modules-skip-2.js').catch(err => msg = err.message);
+
+assertEquals(undefined, life);
+assertEquals(undefined, msg);
+
+%RunMicrotasks();
+
+assertEquals(42, life);
+assertEquals('42 is not the answer', msg);