Obsolete old MIPS SVr3 and SVr4 systems.
* NEWS: Mention obsoleted systems.
* configure.tgt: Mark mips*-*-sysv4* as obsolete.
* configure.host: Mark mips-dec-*, mips-little-*, mips-sony-*,
mips-*-sysv4*, mips-*-sysv*, mips-*-riscos* and mips-*-mach3* as
obsolete.
* config/mips/decstation.mh: Mark as obsolete.
* config/mips/littlemips.mh: Mark as obsolete.
* config/mips/nm-mips.h: Mark as obsolete.
* config/mips/xm-mips.h: Mark as obsolete.
* config/mips/news-mips.mh: Mark as obsolete.
* config/mips/nm-news-mips.h: Mark as obsolete.
* config/mips/riscos.mh: Mark as obsolete.
* config/mips/nm-riscos.h: Mark as obsolete.
* config/mips/xm-riscos.h: Mark as obsolete.
* config/mips/mipsv4.mt: Mark as obsolete.
* config/mips/tm-mipsv4.h: Mark as obsolete.
* config/mips/xm-mipsv4.h: Mark as obsolete.
* config.in: Regenerate with autoheader.
* configure: Regenerate with autoconf.
* inflow.c (_initialize_inflow): Only try to use _SC_JOB_CONTROL
if it is actually defined.
(gdb_setpgid): Use HAVE_SETPGID.
* ch-exp.c: Change include of <string.h> to "gdb_string.h".
* c-exp.y: Ditto.
* f-exp.y: Ditto.
* m2-exp.y: Ditto.
* c-exp.y: Include <ctype.h>.
* serial.c: Ditto.
* config/m68k/nm-news.h: Add typedef for pid_t which is
apparently missing from <sys/types.h>. Enclose entire
file in NM_NEWS_H ifndef and define when included.
* config/mips/nm-news-mips.h: Ditto.
* config/m68k/tm-m68k.h (REGISTER_CONVERT_TO_VIRTUAL,
REGISTER_CONVERT_TO_RAW): Change name of temporary variable.
