libstdc++: Fix OpenBSD ctype_base masks

Building on recent OpenBSD fails because the mask macros have been
redefined.  Use the new macros if available.

libstdc++-v3/ChangeLog:

	* config/os/bsd/openbsd/ctype_base.h: Use _CTYPE prefixed
	macros if available.

Signed-off-by: Pietro Monteiro <pietro@sociotechnical.xyz>
1 file changed