Cygwin: convert __collate_range_cmp to __wcollate_range_cmp

Cygwin: convert __collate_range_cmp to __wcollate_range_cmp

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=179721

After FreeBSD eventually picked up the bugreport from within
only 5 years, rename __collate_range_cmp to __wcollate_range_cmp
as suggested all along, and make it type safe (wint_t instead of
wchar_t for hopefully obvious reasons...)

While at it, drop __collate_load_error and fix the checks for
it in glob and fnmatch.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>