[PATCH] Add support for --with-arch configure option

[Andreas Krebbel]

Hello Roland,

> Please try what I've just committed.

It works - thanks.  If I understand your patch correctly this means
that in case -mcpu and -march are available -mcpu is preferred.  This
is fine for RS6000 and S/390 but I'm not sure that's the right thing
for targets where GCC accepts both options with slightly different
semantics (like ARM).  That's why I've been trying to let the user
choose between -mcpu and -march using different --with-* configure
switches.  This btw would also be equivalent to the configure options
provided by GCC.

But nevertheless the issue I had with S/390 is solved that way. Thanks!

Bye,

-Andreas-