* config/mh-cxux: remove dead code

* config/mh-dgux386: remove dead code
* config/mh-hp300: remove dead code
* config/mh-hpux: remove dead code
* config/mh-hpux8: remove dead code
* config/mh-irix5: remove dead code
* config/mh-irix6: remove dead code
* config/mh-ncr3000: remove dead code
* config/mh-ncrsvr43: remove dead code
* config/mh-necv4: remove dead code
* config/mh-sco: remove dead code
* config/mh-solaris: remove dead code
* config/mh-sysv: remove dead code
* config/mh-sysv4: remove dead code
* config/mh-sysv5: remove dead code
* config/mh-irix4: remove, contains only dead code
* configure.in: delete reference to absent file

configure.in

@@ -173,7 +173,6 @@ case "${host}" in
     # environment.  Also bump switch table size so that cp-parse will
     # compile.  Bump string length limit so linker builds.
     tentative_cc="cc -cckr -Wf,-XNg1500 -Wf,-XNk1000 -Wf,-XNh2000 -Wf,-XNl8192"
-    host_makefile_frag="${host_makefile_frag} config/mh-irix4"
     ;;
   mips*-sgi-irix3*)
     host_makefile_frag="${host_makefile_frag} config/mh-sysv"