Patch for more libiberty cleanups

[DJ Delorie]

> I tested this on sparc-sun-solaris2.7 with "make testlib.a", but
> that's slightly broken in that it tries to build all of the pex-*.c
> files.  Some of those are platform specific and get errors.  (Perhaps
> something to fix in the Makefile?)  So I did "make -k testlib.a"
> instead and visually checked that only the pex-*.c files got failures.

That target was originally added to support a future "make check".  It
probably needs updating.

> -pex-djgpp.o: config.h pex-common.h $(INCDIR)/ansidecl.h $(INCDIR)/libiberty.h
> -pex-mpw.o: config.h pex-common.h $(INCDIR)/ansidecl.h $(INCDIR)/libiberty.h
> -pex-os2.o: config.h pex-common.h $(INCDIR)/ansidecl.h $(INCDIR)/libiberty.h
> -pex-unix.o: config.h pex-common.h $(INCDIR)/ansidecl.h $(INCDIR)/libiberty.h
> -pex-win32.o: config.h pex-common.h $(INCDIR)/ansidecl.h $(INCDIR)/libiberty.h

This can't be right.  Did you use "make maint-deps" to do this?