[modules] Basic support of exports

test/mjsunit/modules-exports3.js

+// Copyright 2016 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.
+
+// MODULE
+
+export { myvar, mylet, myconst };
+
+var myvar = "VAR";
+assertEquals("VAR", myvar);
+let mylet = "LET";
+assertEquals("LET", mylet);
+const myconst = "CONST";
+assertEquals("CONST", myconst);
+
+function* gaga() { yield 1 }
+assertEquals(1, gaga().next().value);
+export {gaga};
+export default gaga;
+export {gaga as gigi};
+assertEquals(1, gaga().next().value);
+
+
+export let gugu = 42;
+
+{
+  assertEquals(42, gugu);
+}
+
+try {
+  assertEquals(42, gugu);
+} catch(_) {
+  assertUnreachable();
+}
+
+try {
+  throw {};
+} catch(_) {
+  assertEquals(42, gugu);
+}
+
+try {
+  throw {};
+} catch({x=gugu}) {
+  assertEquals(42, x);
+}
+
+assertEquals(5, eval("var x = 5; x"));