[regexp] Fix passing all flags to RegExp construction

src/objects.cc

 // 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.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ skipping 16207 matching lines @@
   UNREACHABLE();
   return NULL;
 }
 
 namespace {
 
 JSRegExp::Flags RegExpFlagsFromString(Handle<String> flags, bool* success) {
   JSRegExp::Flags value = JSRegExp::kNone;
   int length = flags->length();
   // A longer flags string cannot be valid.
-  if (length > 5) return JSRegExp::Flags(0);
+  if (length > JSRegExp::FlagCount()) return JSRegExp::Flags(0);
   for (int i = 0; i < length; i++) {
     JSRegExp::Flag flag = JSRegExp::kNone;
     switch (flags->Get(i)) {
       case 'g':
         flag = JSRegExp::kGlobal;
         break;
       case 'i':
         flag = JSRegExp::kIgnoreCase;
         break;
       case 'm':
@@ skipping 4431 matching lines @@
       // depend on this.
       return DICTIONARY_ELEMENTS;
     }
     DCHECK_LE(kind, LAST_ELEMENTS_KIND);
     return kind;
   }
 }
 
 }  // namespace internal
 }  // namespace v8