Replace RE2 import with a dependency

third_party/re2/util/utf.h

-/*
- * The authors of this software are Rob Pike and Ken Thompson.
- *              Copyright (c) 2002 by Lucent Technologies.
- * Permission to use, copy, modify, and distribute this software for any
- * purpose without fee is hereby granted, provided that this entire notice
- * is included in all copies of any software which is or includes a copy
- * or modification of this software and in all copies of the supporting
- * documentation for such software.
- * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
- * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
- * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
- * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
- *
- * This file and rune.cc have been converted to compile as C++ code
- * in name space re2.
- */
-#ifndef RE2_UTIL_UTF_H__
-#define RE2_UTIL_UTF_H__
-
-#include <stdint.h>
-
-namespace re2 {
-
-typedef signed int Rune;        /* Code-point values in Unicode 4.0 are 21 bits wide.*/
-
-enum
-{
-  UTFmax        = 4,            /* maximum bytes per rune */
-  Runesync      = 0x80,         /* cannot represent part of a UTF sequence (<) */
-  Runeself      = 0x80,         /* rune and UTF sequences are the same (<) */
-  Runeerror     = 0xFFFD,       /* decoding error in UTF */
-  Runemax       = 0x10FFFF,     /* maximum rune value */
-};
-
-int runetochar(char* s, const Rune* r);
-int chartorune(Rune* r, const char* s);
-int fullrune(const char* s, int n);
-int utflen(const char* s);
-char* utfrune(const char*, Rune);
-
-}  // namespace re2
-
-#endif  // RE2_UTIL_UTF_H__