Give the union in regex_t a name
Give the union in regex_t a name

Before this commit, when compiling re.c with the options
'-std=c99 -pedantic', the following warning would be given:

re.c:50:4: warning: ISO C99 doesn't support unnamed structs/unions [-Wpedantic]
   50 |   };
      |    ^

This gives the union a name and corrects those places where its members
are referenced.

kokke/tiny-regex-c,kokke/tiny-regex-c