[regexp] Add support for dotAll flag

src/parsing/scanner.cc

 // Copyright 2011 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.
 
 // Features shared by parsing and pre-parsing scanners.
 
 #include "src/parsing/scanner.h"
 
 #include <stdint.h>
 
@@ skipping 1699 matching lines @@
     switch (c0_) {
       case 'g':
         flag = RegExp::kGlobal;
         break;
       case 'i':
         flag = RegExp::kIgnoreCase;
         break;
       case 'm':
         flag = RegExp::kMultiline;
         break;
+      case 's':
+        if (FLAG_harmony_regexp_dotall) {
+          flag = RegExp::kDotAll;
+        } else {
+          return Nothing<RegExp::Flags>();
+        }
+        break;
       case 'u':
         flag = RegExp::kUnicode;
         break;
       case 'y':
         flag = RegExp::kSticky;
         break;
       default:
         return Nothing<RegExp::Flags>();
     }
     if (flags & flag) {
@@ skipping 78 matching lines @@
   // 2, reset the source to the desired position,
   source_->Seek(position);
   // 3, re-scan, by scanning the look-ahead char + 1 token (next_).
   c0_ = source_->Advance();
   Next();
   DCHECK_EQ(next_.location.beg_pos, static_cast<int>(position));
 }
 
 }  // namespace internal
 }  // namespace v8