Revert of Implement flag and source getters on RegExp.prototype.

test/mjsunit/es6/regexp-flags.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: --harmony-regexps --harmony-unicode-regexps
-
-var r1 = /abc/gi;
-assertEquals("abc", r1.source);
-assertTrue(r1.global);
-assertTrue(r1.ignoreCase);
-assertFalse(r1.multiline);
-assertFalse(r1.sticky);
-assertFalse(r1.unicode);
-
-// Internal slot of prototype is not read.
-var r2 = { __proto__: r1 };
-assertThrows(function() { r2.source; }, TypeError);
-assertThrows(function() { r2.global; }, TypeError);
-assertThrows(function() { r2.ignoreCase; }, TypeError);
-assertThrows(function() { r2.multiline; }, TypeError);
-assertThrows(function() { r2.sticky; }, TypeError);
-assertThrows(function() { r2.unicode; }, TypeError);
-
-var r3 = /I/;
-var string = "iIiIi";
-var expected = "iXiIi";
-assertFalse(r3.global);
-assertFalse(r3.ignoreCase);
-assertEquals("", r3.flags);
-assertEquals(expected, string.replace(r3, "X"));
-
-var get_count = 0;
-Object.defineProperty(r3, "global", {
-  get: function() { get_count++; return true; }
-});
-Object.defineProperty(r3, "ignoreCase", {
-  get: function() { get_count++; return true; }
-});
-
-assertTrue(r3.global);
-assertEquals(1, get_count);
-assertTrue(r3.ignoreCase);
-assertEquals(2, get_count);
-// Overridden flag getters affects the flags getter.
-assertEquals("gi", r3.flags);
-assertEquals(4, get_count);
-// Overridden flag getters do not affect the internal flags.
-assertEquals(expected, string.replace(r3, "X"));
-assertEquals(4, get_count);