Fix y-umlaut to uppercase.

src/unicode.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 217 matching lines @@
   static bool Is(uchar c);
 };
 struct CombiningMark {
   static bool Is(uchar c);
 };
 struct ConnectorPunctuation {
   static bool Is(uchar c);
 };
 struct ToLowercase {
   static const int kMaxWidth = 3;
+  static const bool kIsToLower = true;
   static int Convert(uchar c,
                      uchar n,
                      uchar* result,
                      bool* allow_caching_ptr);
 };
 struct ToUppercase {
   static const int kMaxWidth = 3;
+  static const bool kIsToLower = false;
   static int Convert(uchar c,
                      uchar n,
                      uchar* result,
                      bool* allow_caching_ptr);
 };
 struct Ecma262Canonicalize {
   static const int kMaxWidth = 1;
   static int Convert(uchar c,
                      uchar n,
                      uchar* result,
@@ skipping 10 matching lines @@
   static const int kMaxWidth = 1;
   static int Convert(uchar c,
                      uchar n,
                      uchar* result,
                      bool* allow_caching_ptr);
 };
 
 }  // namespace unibrow
 
 #endif  // V8_UNICODE_H_