[PATCH] Fixes for OpenBSD amd64/powerpc/mips64 support

[Rafael Espíndola]

> Possibly but I'd prefer to be conservative with this addition so I can
> get this into 3.4. Such refactoring would also take into consideration
> the assembler handling for Bitrig, FreeBSD, DragonFly, NetBSD, AuroraUX, and
> probably Minix.

This is incurring technical debt, which is fine if we pay for it. Are
you ok with working on a patch to change at least openbsd to use
gnutools::Assemble::ConstructJob once this patch is in?

Since the purpose of the patch is to be portable to 3.4, it is fine by
me if Bill thinks it would be OK to port it to 3.4.

Cheers,
Rafael