* configure.in: Add new check to see if compiler supports
aliasing of arrays and define _HAVE_ARRAY_ALIASING if true.
* configure: Regenerated.
* Makefile.in: Ditto.
* newlib.hin: Add _HAVE_ARRAY_ALIASING.
* libc/ctype/ctype_.c: Check for _HAVE_ARRAY_ALIASING before
aliasing the _ctype_ array to _ctype_b.
* libc/include/ctype.h: Change macros to use __ctype_ptr. Mark
_ctype_ as deprecated.