mh-cxux: remove dead code

mh-cxux: remove dead code

* 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

From-SVN: r52926