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

Reland of Put RegExp js code in strict mode (patchset #2 id:20001 of https://codereview.chromium.or… (patchset #2 id:20001 of https://codereview.chromium.org/2112713003/ )

Reason for revert:
With fixes for frozen RegExps in https://codereview.chromium.org/2339443002 , it should be web-compatible to put RegExps in strict mode again, per spec.

Original issue's description:
> 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
>
> Committed: https://crrev.com/34880eb3dcf7492d44c0a3b45b6c888189f2c3c3
> Cr-Commit-Position: refs/heads/master@{#37449}

TBR=adamk@chromium.org,yangguo@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:624318

Review-Url: https://codereview.chromium.org/2344773002
Cr-Commit-Position: refs/heads/master@{#39456}

src/js/regexp.js

@@ -4,6 +4,8 @@
 
 (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 only for global or sticky RegExps. On failure to find
+// a match, it is set to 0. If a set fails, then it acts as if in strict mode
+// and throws.
+
+var re = /x/g;
+Object.defineProperty(re, 'lastIndex', {writable: false});
+assertThrows(() => re.exec(""), TypeError);
+assertThrows(() => re.exec("x"), TypeError);
+
+var re = /x/y;
+Object.defineProperty(re, 'lastIndex', {writable: false});
+assertThrows(() => re.exec(""), TypeError);
+assertThrows(() => re.exec("x"), TypeError);
+
+var re = /x/;
+Object.defineProperty(re, 'lastIndex', {writable: false});
+assertEquals(null, re.exec(""));
+assertEquals(["x"], re.exec("x"));

test/test262/test262.status

@@ -106,19 +106,8 @@
   'built-ins/RegExp/prototype/Symbol.replace/y-set-lastindex': [FAIL],
 
   # https://bugs.chromium.org/p/v8/issues/detail?id=5360
-  '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],
+  'built-ins/RegExp/prototype/Symbol.match/builtin-failure-set-lastindex-err': [FAIL],
+  'built-ins/RegExp/prototype/Symbol.search/set-lastindex-restore-err': [FAIL],
 
   # https://bugs.chromium.org/p/v8/issues/detail?id=5123
   'built-ins/RegExp/prototype/Symbol.replace/coerce-global': [FAIL],

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

@@ -44,8 +44,8 @@ PASS Object.defineProperty(Object.defineProperty(/x/, 'lastIndex', {writable:fal
 PASS Object.defineProperty(Object.defineProperty(/x/, 'lastIndex', {writable:false}), 'lastIndex', {value:0}); true is true
 PASS Object.defineProperty(/x/, 'lastIndex', {writable:false}).exec('') is null
 PASS Object.defineProperty(/x/, 'lastIndex', {writable:false}).exec('x') is ["x"]
-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 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]'.
 PASS var re = /x/; Object.freeze(re); Object.isFrozen(re); is true
 PASS successfullyParsed is true