Remove the global Strength enum class completely.

test/mjsunit/es6/classes-subclass-builtins.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: --allow-natives-syntax --harmony-reflect --harmony-regexp-subclass
 // Flags: --expose-gc --strong-mode
 
 "use strict";
 
 
@@ skipping 60 matching lines @@
 
   gc();
 })();
 
 
 (function() {
   class A extends Function {
     constructor(...args) {
       assertFalse(new.target === undefined);
       super(...args);
-      // Strong functions are not extensible, so don't add fields.
-      if (args[args.length - 1].indexOf("use strong") >= 0) {
-        assertThrows(()=>{ this.a = 10; }, TypeError);
-        return;
-      }
       this.a = 42;
       this.d = 4.2;
       this.o = {foo:153};
     }
   }
   var sloppy_func = new A("");
   var strict_func = new A("'use strict';");
   assertNull(sloppy_func.caller);
   assertThrows("strict_f.caller");
   assertNull(Object.getOwnPropertyDescriptor(sloppy_func, "caller").value);
@@ skipping 556 matching lines @@
   assertTrue(%HaveSameMap(sloppy_func, sloppy_func1));
 
   // Strict generator function
   var strict_func = new A("'use strict'; " + source);
   assertFalse(%HaveSameMap(strict_func, sloppy_func));
   CheckFunction(strict_func, false);
 
   var strict_func1 = new A("'use strict'; yield 312;");
   assertTrue(%HaveSameMap(strict_func, strict_func1));
 
-  // Strong generator function
-  var strong_func = new A("'use strong'; " + source);
-  assertFalse(%HaveSameMap(strong_func, sloppy_func));
-  assertFalse(%HaveSameMap(strong_func, strict_func));
-  CheckFunction(strong_func, true);
-
-  var strong_func1 = new A("'use strong'; yield 312;");
-  assertTrue(%HaveSameMap(strong_func, strong_func1));
-
   gc();
 })();
 
 
 (function() {
   class A extends Promise {
     constructor(...args) {
       assertFalse(new.target === undefined);
       super(...args);
       this.a = 42;
@@ skipping 266 matching lines @@
 
   Object.defineProperty(pattern, Symbol.match, {
     get() { log.push("match"); f.prototype = p2; return false; }});
 
   var o = Reflect.construct(RegExp, [pattern], f);
   assertEquals(["match", "tostring"], log);
   assertEquals(/biep/, o);
   assertTrue(o.__proto__ === p2);
   assertTrue(f.prototype === p3);
 })();