libiberty: purge MPW support

[Stan Shebs]

Zack Weinberg wrote:
> 
> This patch removes all support for MPW from libiberty.

Whacking MPW bits has been on my todo list for awhile.  Apple has
recently reassigned Greg Branche, who the last person who was
supporting MPW, so the pulse is almost gone.  On the other hand,
Alex Rosenberg has been working on reviving the MPW port recently
(MPW still has a fan club unhappy that Apple is dropping it), and
so I wanted to give the MPWers a last chance to sign up to keeping
this port alive.

> This host is
> obsolete, and does not appear to have worked for some time.  For
> instance, the code in gcc which uses pexecute assumes that the
> subprocess starts immediately; this does not happen under MPW.  The
> pfinish() routine which I removed from the exported interface is
> referenced nowhere in GCC, GDB, and binutils.  (I don't have a
> complete /cvs/src checkout just now to grep through.)

I think gcc.c used to call it - probably in code that didn't get
carried over when egcs was created.

Stan