[DotGNU]libffi and thus pnet will not compile under hpux11

[James Mc Parlane]

I managed to get treecc compiling after downgrading automake to 1.4 (Thanks
to ajmitch on the irc server for helping me last night). hpux's built in lex
was not good enough so I had to install flex (if all versions of lex are
contra-indicated for pnet it would be good if configure could stop and
insist on flex). I already had GNU Bison version 1.28 installed.

When I came to build pnet. ./configure seemed to work...  but make failed
"*** No rule to make target `all'." Closer examination of the output showed
that it was failing in the libffi directory. A cd libffi and a ./configure
spat out a "configure: error: libffi has not been ported to
hppa2.0w-hp-hpux11.00."

So I can't run pnet on my hpux box... :(

A quick squiz at the libffi pages reveals that they consider hp and aix to
be "very hard"TM.