Replace RE2 import with a dependency

third_party/re2/re2/unicode_groups.h

Index: third_party/re2/re2/unicode_groups.h
diff --git a/third_party/re2/re2/unicode_groups.h b/third_party/re2/re2/unicode_groups.h
deleted file mode 100644
index fc1c2534d6799ca76a61ba14fc7eff898acf40b5..0000000000000000000000000000000000000000
--- a/third_party/re2/re2/unicode_groups.h
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright 2008 The RE2 Authors.  All Rights Reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Unicode character groups.
-
-// The codes get split into ranges of 16-bit codes
-// and ranges of 32-bit codes.  It would be simpler
-// to use only 32-bit ranges, but these tables are large
-// enough to warrant extra care.
-//
-// Using just 32-bit ranges gives 27 kB of data.
-// Adding 16-bit ranges gives 18 kB of data.
-// Adding an extra table of 16-bit singletons would reduce
-// to 16.5 kB of data but make the data harder to use;
-// we don't bother.
-
-#ifndef RE2_UNICODE_GROUPS_H__
-#define RE2_UNICODE_GROUPS_H__
-
-#include "util/util.h"
-
-namespace re2 {
-
-struct URange16
-{
-  uint16 lo;
-  uint16 hi;
-};
-
-struct URange32
-{
-  Rune lo;
-  Rune hi;
-};
-
-struct UGroup
-{
-  const char *name;
-  int sign;  // +1 for [abc], -1 for [^abc]
-  const URange16 *r16;
-  int nr16;
-  const URange32 *r32;
-  int nr32;
-};
-
-// Named by property or script name (e.g., "Nd", "N", "Han").
-// Negated groups are not included.
-extern const UGroup unicode_groups[];
-extern const int num_unicode_groups;
-
-// Named by POSIX name (e.g., "[:alpha:]", "[:^lower:]").
-// Negated groups are included.
-extern const UGroup posix_groups[];
-extern const int num_posix_groups;
-
-// Named by Perl name (e.g., "\\d", "\\D").
-// Negated groups are included.
-extern const UGroup perl_groups[];
-extern const int num_perl_groups;
-
-}  // namespace re2
-
-#endif  // RE2_UNICODE_GROUPS_H__