alpha: Modernize lib/mpi/longlong.h
alpha: Modernize lib/mpi/longlong.h

Remove the compile warning for __udiv_qrnnd not having a prototype.
Use the __builtin_alpha_umulh introduced in gcc 4.0.

Reviewed-and-Tested-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>
Signed-off-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>
Signed-off-by: Richard Henderson <aea4fd857e97ee7d33f60175ba9388a955b9d916@twiddle.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs