Update re2

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
index f91c51f5d89c06252ddc6576cd50e26278fe01d0..fc1c2534d6799ca76a61ba14fc7eff898acf40b5 100644
--- a/third_party/re2/re2/unicode_groups.h
+++ b/third_party/re2/re2/unicode_groups.h
@@ -30,34 +30,34 @@ struct URange16
 
 struct URange32
 {
-  uint32 lo;
-  uint32 hi;
+  Rune lo;
+  Rune hi;
 };
 
 struct UGroup
 {
   const char *name;
   int sign;  // +1 for [abc], -1 for [^abc]
-  URange16 *r16;
+  const URange16 *r16;
   int nr16;
-  URange32 *r32;
+  const URange32 *r32;
   int nr32;
 };
 
 // Named by property or script name (e.g., "Nd", "N", "Han").
 // Negated groups are not included.
-extern UGroup unicode_groups[];
-extern int num_unicode_groups;
+extern const UGroup unicode_groups[];
+extern const int num_unicode_groups;
 
 // Named by POSIX name (e.g., "[:alpha:]", "[:^lower:]").
 // Negated groups are included.
-extern UGroup posix_groups[];
-extern int num_posix_groups;
+extern const UGroup posix_groups[];
+extern const int num_posix_groups;
 
 // Named by Perl name (e.g., "\\d", "\\D").
 // Negated groups are included.
-extern UGroup perl_groups[];
-extern int num_perl_groups;
+extern const UGroup perl_groups[];
+extern const int num_perl_groups;
 
 }  // namespace re2