Renamed more constants to avoid exporting

regex/nfa.go

@@ -198,7 +198,7 @@ func (s nfaState) matchesFor(str []rune, idx int) ([]*nfaState, int) {
 		}
 	}
 	listTransitions := s.transitions[int(str[idx])]
-	for _, dest := range s.transitions[int(ANY_CHAR)] {
+	for _, dest := range s.transitions[int(anyCharRune)] {
 		if !slices.Contains(slices.Concat(notDotChars, dest.except), str[idx]) {
 			// Add an allChar state to the list of matches if:
 			// 		a. The current character isn't a 'notDotChars' character. In single line mode, this includes newline. In multiline mode, it doesn't.