* NEWS: Mention that the i[3456]-*-aix target has been made obsolete.

* NEWS: Mention that the i[3456]-*-aix target has been made obsolete.
* configure.host: Make i[3456]86-*-aix host obsolete.
* configure.tgt: Make i[3456]86-*-aix target obsolete.
* config/i386/i386aix.mh, config/i386/i386aix.mt,
config/i386/nm-i386aix.h, condig/i386/tm-i386aix.h,
config/i386/xm-i386aix.h: Make files obsolete.
* i386aix-nat.c: Make file obsolete.
* Makefile.in (ALLDEPFILES): Remove i386aix-nat.c.
(i386aix-nat.o): Make target obsolete.