In addition to the automatic changes, also do the following,
needed due to recent Gnulib changes.
* admin/merge-gnulib (AVOIDED_MODULES): Add btoc32,
c32_apply_type_test, c32_get_type_test, c32isalnum, c32rtomb,
c32tolower, c32toupper, localeinfo, mbrtoc32-regular.
Remove btowc, iswctype, mbrtowc, wcrtomb, wctype, wctype-h.
Also remove iswblank, iswdigit, iswxdigit, locale-h, raise,
stdarg-h, some of which perhaps could have been removed earlier.
* configure.ac (_REGEX_AVOID_UCHAR_H): New macro.
