[strong] Check constructor returns

test/mjsunit/strong/classes.js

 // Copyright 2015 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: --strong-mode
 // Flags: --harmony-classes --harmony-arrow-functions
 
 'use strong';
 
 class C {}
@@ skipping 14 matching lines @@
   return "'use strong'; " +
       "(class extends Object { constructor() { " + body + " } })";
 }
 
 (function NoMissingSuper() {
   assertReferenceError(constructor(""));
   assertReferenceError(constructor("1"));
 })();
 
 (function NoNestedSuper() {
-  assertSyntaxError(constructor("(super())"));
-  assertSyntaxError(constructor("(() => super())(); } })"));
-  assertSyntaxError(constructor("{ super();"));
+  assertSyntaxError(constructor("(super());"));
+  assertSyntaxError(constructor("(() => super())();"));
+  assertSyntaxError(constructor("{ super(); }"));
   assertSyntaxError(constructor("if (1) super();"));
 })();
 
 (function NoDuplicateSuper() {
   assertSyntaxError(constructor("super(), super();"));
   assertSyntaxError(constructor("super(); super();"));
   assertSyntaxError(constructor("super(); (super());"));
   assertSyntaxError(constructor("super(); { super() }"));
+  assertSyntaxError(constructor("super(); (() => super())();"));
 })();
+
+(function NoReturnValue() {
+  assertSyntaxError(constructor("return {};"));
+  assertSyntaxError(constructor("return undefined;"));
+  assertSyntaxError(constructor("{ return {}; }"));
+  assertSyntaxError(constructor("if (1) return {};"));
+})();
+
+(function NoReturnBeforeSuper() {
+  assertSyntaxError(constructor("return; super();"));
+  assertSyntaxError(constructor("if (0) return; super();"));
+  assertSyntaxError(constructor("{ return; } super();"));
+})();