PERFORCE change 134769 for review

[Warner Losh]

> * M. Warner Losh <imp at bsdimp.com> wrote:
> > I don't think you want this change.  it is wrong because we don't
> > support ISA_MIPS64's notion of 64-bit registers correctly.
> 
> Just tracking the commits a little; you mean that the MIPS port doesn't
> yet support 64 bits registers in the CPU context switching code?

I mean that it doesn't support saving 64-bit registers when compiled
for 32-bit operation.  Just adding ISA_MIPS64 doesn't change the fact
that the kernel is built with the o32 abi.  Most fo the code to
support the change is in place, but hasn't been fleshed out in a few
key areas.

Warner