[parser] disallow language mode directive in body of function with non-simple parameters

test/mjsunit/strong/literals.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 --allow-natives-syntax
 // Flags: --harmony-arrow-functions --harmony-rest-parameters
 // Flags: --harmony-destructuring --harmony-spread-arrays
 
 'use strict';
 
@@ skipping 94 matching lines @@
   assertWeakArray([1, 2, 3]);
   assertWeakArray([1, 2, ...[3, 4], 5]);
   assertWeakArray([[[]]]);
   assertWeakArray([[1], {}, [[3]]]);
   assertWeakArray([[1], {}, [[3]]][0]);
   assertWeakArray([[1], {}, [[3]]][2]);
   assertWeakArray([[1], {}, [[3]]][2][0]);
   assertWeakArray({a: [], b: {}}.a);
 })();
 
-(function StrongArrayLiterals(...args) {
+(function StrongArrayLiterals() {
   'use strong';
   function assertStrongArray(x) {
     assertTrue(%IsStrong(x));
     assertSame(Array.prototype, Object.getPrototypeOf(x));
   }
   let [...r] = [];
-  assertStrongArray(args);
+  assertStrongArray((function(...a) { return a; })());
   assertStrongArray(r);
   assertStrongArray([]);
   assertStrongArray([1, 2, 3]);
   assertStrongArray([1, 2, ...[3, 4], 5]);
   assertStrongArray([[[]]]);
   assertStrongArray([[1], {}, [[3]]]);
   assertStrongArray([[1], {}, [[3]]][0]);
   assertStrongArray([[1], {}, [[3]]][2]);
   assertStrongArray([[1], {}, [[3]]][2][0]);
   assertStrongArray({a: [], b: {}}.a);
@@ skipping 210 matching lines @@
 })();
 
 (function StrongRegExpLiterals() {
   'use strong';
   function assertStrongRegExp(x) {
     // TODO(rossberg): strongify regexps
     // assertTrue(%IsStrong(x));
   }
   assertStrongRegExp(/abc/);
 })();