Use ICU for ID_START and ID_CONTINUE for Unicode 9 data

src/unicode.h

 // 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.
 
 #ifndef V8_UNICODE_H_
 #define V8_UNICODE_H_
 
 #include <sys/types.h>
 #include "src/globals.h"
 #include "src/utils.h"
@@ skipping 154 matching lines @@
 
   // Excludes non-characters from the set of valid code points.
   static inline bool IsValidCharacter(uchar c);
 
   static bool Validate(const byte* str, size_t length);
 };
 
 struct Uppercase {
   static bool Is(uchar c);
 };
-struct Lowercase {
-  static bool Is(uchar c);
-};
 struct Letter {
   static bool Is(uchar c);
 };
+#ifndef V8_INTL_START
 struct V8_EXPORT_PRIVATE ID_Start {
   static bool Is(uchar c);
 };
 struct V8_EXPORT_PRIVATE ID_Continue {
   static bool Is(uchar c);
 };
 struct V8_EXPORT_PRIVATE WhiteSpace {
   static bool Is(uchar c);
 };
 struct V8_EXPORT_PRIVATE LineTerminator {
   static bool Is(uchar c);
 };
+#endif  // !V8_INTL_SUPPORT
 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;
@@ skipping 21 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_