64bit support for unix

[Brad Lucier]

> subreg_byte is necessary condition.
> Have you tried configuring gcc for sparcv9-sun-solaris?

Yes, I tried various ways to build it, no, it doesn't bootstrap.
A few details are on gcc-bugs.

> It certainly works for sparc64-*-linux (to some extent).

I remember you posting some very impressive test results on linux
from last July, so I've been looking forward to the subreg-byte
changes being integrated into gcc, but trying to get a bootstrap to
work on solaris2.8 has just been frustrating.

Brad