Remove separate locale_is_c arguments

Remove separate locale_is_c arguments

Since e9931bfb751, ctype_is_c is part of pg_locale_t.  Some functions
passed a pg_locale_t and a bool argument separately.  This can now be
combined into one argument.

Since some callers call MatchText() with locale 0, it is a bit
confusing whether this is all correct.  But it is the case that only
callers that pass a non-zero locale object to MatchText() end up
checking locale->ctype_is_c.  To make that flow a bit more
understandable, add the locale argument to MATCH_LOWER() and GETCHAR()
in like_match.c, instead of implicitly taking it from the outer scope.

Reviewed-by: Jeff Davis <pgsql@j-davis.com>
Discussion: https://www.postgresql.org/message-id/84d415fc-6780-419e-b16c-61a0ca819e2b@eisentraut.org