* etc/MACHINES: Misc small edits.

Update Irix info.  Remove details of obsoleted platforms.

etc/MACHINES

@@ -102,103 +102,21 @@ the list at the end of this file.
 
 ** Irix 6.5
 
-  It *may* be possible to build Emacs on Irix 6.5 with an old version
-  (3.1) of gcc.  Newer versions of gcc may not work.  None of the
-  current Emacs developers use Irix, though.  If you want to help
-  make Emacs on Irix work, see <http://debbugs.gnu.org/9684>.
+  Emacs versions later than 24.4 will not compile on Irix by default.
+  (Note that SGI stopped supporting Irix in December 2013.)
+  You should be able to work around the problem either by porting the
+  Emacs undumping code to GCC under Irix, or by configuring --with-wide-int.
+  Older versions of Emacs 24 (and 23?) also had problems on Irix.
+  It *may* be possible to build Emacs <= 24.4 on Irix 6.5 with an old
+  version (3.1) of gcc.  Newer versions of gcc may not work.
+  See <http://debbugs.gnu.org/9684>.
 
 
 * Obsolete platforms
 
-Support for the following obsolete platforms was removed in Emacs 23.1
-(the names in parentheses state the files in src/ that were removed):
-
-  Apollo SR10.x (unexapollo.c)
-  Convex (unexconvex.c and m/convex.c)
-  Xenix (unexenix.c and s/xenix.h)
-  Iris  (unexmips.c m/iris4d.h m/irist.h s/iris3-5.h s/iris3-6.h)
-  Gould (m/gould*)
-  Siemens machines running Sinix (unexsni.c)
-  Harris CXUX (s/cxux*)
-  ESIX, a variant of v.5.3 for the 386 (s/esix*)
-  Interactive (ISC) Unix (s/isc*)
-  Sony News (s/newsos*)
-  RTU 3.0, ucb universe (s/rtu.h)
-  UniSoft's UniPlus 5.2 (s/uniplus.h)
-  UMAX (s/umax.h)
-  AT&T UNIX PC model 7300 (m/7300.h)
-  Acorn
-  Alliant (m/alliant*)
-  Amdahl (m/amdahl*)
-  Altos 3068 Unix System V Release 2 (m/altos.h)
-  Apollo (m/apollo.h)
-  AT&T 3b (m/att3b.h)
-  Aviion (m/aviion*)
-  Berkeley 4.1 (m/bsd4.1.h)
-  Berkeley 4.2 (m/bsd4.2.h)
-  Berkeley 4.3 (m/bsd4.3.h)
-  Celerity (m/celerity.h)
-  clipper (m/clipper.h)
-  convergent S series (m/cnvrgnt.h)
-  cydra (m/cydra5.h)
-  Motorola System V/88 machines (m/delta88k.h)
-  Bull DPX/2 range (m/dpx2.h)
-  Dual machines using unisoft port (m/dual.h)
-  Elxsi machine (running enix) (m/elxsi.h)
-  Fujitsu F301 machine (m/f301.h)
-  i860 (m/i860.h)
-  ibm ps/2 aix386 (m/ibmps2-aix.h)
-  ISI 68000's (m/is*)
-  Masscomp 5000 series running RTU, ucb universe (m/masscomp.h)
-  Megatest 68000's (m/mega68.h)
-  Whitechapel Computer Works MG1 (ns16000 based) (m/mg1.h)
-  Harris Night Hawk Series 1200 and Series 3000 (m/nh3000.h m/nh4000.h)
-  ns16000 (m/ns16000.h)
-  National Semiconductor 32000, running Genix (m/ns32000.h)
-  TI Nu machines using system V (m/nu.h)
-  HLH Orion (m/orion.h m/orion105.h)
-  Paragon i860 (m/paragon.h)
-  PFU A-series (m/pfa50.h)
-  Plexus running System V.2 (m/plexus.h)
-  pyramid. (m/pyramid.h)
-  Bull SPS-7 (m/sps7.h)
-  Hitachi SR2001/SR2201 (m/sr2k.h)
-  Stride (m/stride.h)
-  Sun 1 (m/sun1.h)
-  Sun 2 (m/sun2.h)
-  SEQUENT SYMMETRY  (m/symmetry.h)
-  Tadpole 68k machines (m/tad68k.h)
-  tahoe (m/tahoe.h)
-  targon31 (m/targon31.h)
-  Tektronix* (m/tek4300.h m/tekxd88.h)
-  NCR Tower 32 running System V.2 (m/tower32.h)
-  NCR Tower 32 running System V.3 (m/tower32v3.h)
-  U-station (Nihon Unisys, SS5E; Sumitomo Denkoh, U-Station E30) (m/ustation.h)
-  Wicat (m/wicat.h)
-  Honeywell XPS100 running UNIX System V.2 (m/xps100.h)
-  Data General's DG/UX  (s/dgux*)
-  Irix before version 6
-  osf1 (s/osf*)
-  SunOS4 (s/sunos*)
-  RISCiX (s/riscix*)
-  SCO 3.2v4 (s/sco4.h)
-  SCO 3.2v5 (s/sco5.h)
-  Sun's 386-based RoadRunner (m/sun386.h)
-  Sun3 machines (m/sun3*)
-  Integrated Solutions 386 machine (m/is386.h)
-  Integrated Solutions `Optimum V' -- m68k-isi-bsd4.2 or -bsd4.3
-  Harris Power PC (powerpc-harris-powerunix)
-  Hewlett-Packard 9000 series 200 or 300 on some platforms -- m68k-hp-bsd or
-    m68k-hp-hpux; note m68k-*-netbsd* still works
-  IBM PS/2 -- i386-ibm-aix1.1 or i386-ibm-aix1.2
-  GEC 63 -- local-gec63-usg5.2
-  Tandem Integrity S2 -- mips-tandem-sysv
-  System V rel 0 -- usg5.0
-  System V rel 2 -- usg5.2
-  System V rel 2.2 -- usg5.2.2
-  System V rel 3 -- usg5.3
-  Ultrix -- bsd4.3
-  VMS (s/vms.h)
+Support for many obsolete platforms was removed in Emacs 23.1.
+If for some reason you encounter an ancient machine where current
+Emacs does not compile, try an older release like Emacs 22.3.
 
 
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