[regexp] Fix passing all flags to RegExp construction

src/objects.h

 // 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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 #include <memory>
 
@@ skipping 7398 matching lines @@
   // IRREGEXP: Compiled with Irregexp.
   enum Type { NOT_COMPILED, ATOM, IRREGEXP };
   enum Flag {
     kNone = 0,
     kGlobal = 1 << 0,
     kIgnoreCase = 1 << 1,
     kMultiline = 1 << 2,
     kSticky = 1 << 3,
     kUnicode = 1 << 4,
     kDotAll = 1 << 5,
+    // Update FlagCount when adding new flags.
   };
   typedef base::Flags<Flag> Flags;
 
+  static int FlagCount() { return FLAG_harmony_regexp_dotall ? 6 : 5; }
+
   DECL_ACCESSORS(data, Object)
   DECL_ACCESSORS(flags, Object)
   DECL_ACCESSORS(source, Object)
 
   V8_EXPORT_PRIVATE static MaybeHandle<JSRegExp> New(Handle<String> source,
                                                      Flags flags);
   static Handle<JSRegExp> Copy(Handle<JSRegExp> regexp);
 
   static MaybeHandle<JSRegExp> Initialize(Handle<JSRegExp> regexp,
                                           Handle<String> source, Flags flags);
@@ skipping 2869 matching lines @@
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #include "src/objects/object-macros-undef.h"
 
 #endif  // V8_OBJECTS_H_