Revert of Put RegExp js code in strict mode (patchset #2 id:20001 of...

Revert of Put RegExp js code in strict mode (patchset #2 id:20001 of https://codereview.chromium.org/1776883005/ )

Reason for revert:
Found to break SAP Web IDE, and these semantics are not shipped in any other browser.
Revert to legacy semantics while assessing web compatibility.

BUG=chromium:624318

Original issue's description:
> Put RegExp js code in strict mode
>
> src/js/regexp.js was one of the few files that was left in sloppy
> mode. The ES2017 draft specification requires that writes to
> lastIndex throw when the property is non-writable, and test262
> tests enforce this behavior. This patch puts that file in strict
> mode.
>
> BUG=v8:4504
> R=yangguo@chromium.org
> LOG=Y
>
> Committed: https://crrev.com/80b1b2a45bbd9bf3d08e4e6516acfaaa8f438213
> Cr-Commit-Position: refs/heads/master@{#34801}

TBR=yangguo@chromium.org,adamk@chromium.org

Review-Url: https://codereview.chromium.org/2112713003
Cr-Commit-Position: refs/heads/master@{#37449}

src/js/regexp.js

@@ -4,8 +4,6 @@
 
 (function(global, utils) {
 
-'use strict';
-
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------

test/mjsunit/regexp-lastIndex.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.
-
-// lastIndex is set according to funny rules. It is typically set only
-// for global or sticky RegExps, but on a failure to find a match, it is
-// set unconditionally. If a set fails, then it acts as if in strict mode
-// and throws.
-
-var re = /x/;
-Object.defineProperty(re, 'lastIndex', {writable: false});
-assertThrows(() => re.exec(""), TypeError);
-assertEquals(["x"], re.exec("x"));
-
-var re = /x/y;
-Object.defineProperty(re, 'lastIndex', {writable: false});
-assertThrows(() => re.exec(""), TypeError);
-assertThrows(() => re.exec("x"), TypeError);

test/test262/test262.status

@@ -111,6 +111,22 @@
   'built-ins/RegExp/prototype/Symbol.replace/y-init-lastindex': [FAIL],
   'built-ins/RegExp/prototype/Symbol.replace/y-set-lastindex': [FAIL],
 
+  # https://code.google.com/p/v8/issues/detail?id=4504
+  # https://bugs.chromium.org/p/chromium/issues/detail?id=624318
+  'built-ins/RegExp/prototype/Symbol.match/builtin-failure-set-lastindex-err': [PASS, FAIL],
+  'built-ins/RegExp/prototype/Symbol.match/builtin-failure-y-set-lastindex-err': [PASS, FAIL],
+  'built-ins/RegExp/prototype/Symbol.match/builtin-success-g-set-lastindex-err': [SKIP],
+  'built-ins/RegExp/prototype/Symbol.match/builtin-success-y-set-lastindex-err': [PASS, FAIL],
+  'built-ins/RegExp/prototype/Symbol.match/g-init-lastindex-err': [PASS, FAIL],
+  'built-ins/RegExp/prototype/Symbol.match/g-match-empty-set-lastindex-err': [PASS, FAIL],
+  'built-ins/RegExp/prototype/Symbol.match/y-fail-lastindex-no-write': [PASS, FAIL],
+  'built-ins/RegExp/prototype/Symbol.replace/g-init-lastindex-err': [PASS, FAIL],
+  'built-ins/RegExp/prototype/Symbol.replace/y-fail-lastindex-no-write': [PASS, FAIL],
+  'built-ins/RegExp/prototype/Symbol.search/set-lastindex-init-err': [PASS, FAIL],
+  'built-ins/RegExp/prototype/Symbol.search/set-lastindex-restore-err': [PASS, FAIL],
+  'built-ins/RegExp/prototype/exec/y-fail-lastindex-no-write': [PASS, FAIL],
+  'built-ins/RegExp/prototype/test/y-fail-lastindex-no-write': [PASS, FAIL],
+
   # SKIP rather than FAIL, as the test checks for an exception which
   # happens to be thrown for some other reason.
   'built-ins/RegExp/prototype/Symbol.split/str-result-get-length-err': [SKIP],

test/webkit/fast/regex/lastIndex-expected.txt

@@ -42,10 +42,10 @@ PASS var re = Object.defineProperty(/x/, 'lastIndex', {value:42}); re.lastIndex
 PASS Object.defineProperty(Object.defineProperty(/x/, 'lastIndex', {writable:false}), 'lastIndex', {writable:true}); true threw exception TypeError: Cannot redefine property: lastIndex.
 PASS Object.defineProperty(Object.defineProperty(/x/, 'lastIndex', {writable:false}), 'lastIndex', {value:42}); true threw exception TypeError: Cannot redefine property: lastIndex.
 PASS Object.defineProperty(Object.defineProperty(/x/, 'lastIndex', {writable:false}), 'lastIndex', {value:0}); true is true
-FAIL Object.defineProperty(/x/, 'lastIndex', {writable:false}).exec('') should be null. Threw exception TypeError: Cannot assign to read only property 'lastIndex' of object '[object RegExp]'
+PASS Object.defineProperty(/x/, 'lastIndex', {writable:false}).exec('') is null
 PASS Object.defineProperty(/x/, 'lastIndex', {writable:false}).exec('x') is ["x"]
-PASS Object.defineProperty(/x/g, 'lastIndex', {writable:false}).exec('') threw exception TypeError: Cannot assign to read only property 'lastIndex' of object '[object RegExp]'.
-PASS Object.defineProperty(/x/g, 'lastIndex', {writable:false}).exec('x') threw exception TypeError: Cannot assign to read only property 'lastIndex' of object '[object RegExp]'.
+FAIL Object.defineProperty(/x/g, 'lastIndex', {writable:false}).exec('') should throw an exception. Was null.
+FAIL Object.defineProperty(/x/g, 'lastIndex', {writable:false}).exec('x') should throw an exception. Was x.
 PASS var re = /x/; Object.freeze(re); Object.isFrozen(re); is true
 PASS successfullyParsed is true