Updating top-level autoconf to 2.59

[Steve Ellcey]

> Aha!  This is the issue I fixed for subdirectories on 2003-09-21.
> I think we shouldn't "fix" this, but I'm open to comments; this
> is one of the changes in autoconf we've been putting off.

So what would be the 'proper' way to specify a native GCC build on a
target without having to use config.guess?  For example, on a PA2.0
machine config.guess would return hppa2.0w-hp-hpux11.11 but maybe I want
to make a PA1.1 compiler (hppa1.1-hp-hpux11.11) on this PA2.0 box so
that it will work on PA1.1 boxes as well as PA2.0 boxes.  But I want the
compiler as gcc, not hppa1.1-hp-hpux11.11-gcc.  How should I specify
this?

Steve Ellcey
sje@cup.hp.com