FreeBSD mips support

Greetings,

I think it may be about time to remove MIPS support from the tree. The last
major users have moved on, and the port suffers from a number of problems
on modern systems with modern workloads. We have a number of workarounds in
the tree for different aspects of the mips port that we could retire as
well...

I'd like to propose removal of mips from -current soon, say by the end of
the year.

Comments?

Warner