PMAP_DIAGNOSTIC was eliminated from amd64/i386, and, in fact, the
non-MIPS parts of the kernel, several years ago. Any of the interesting
checks were turned into KASSERT()s. Basically, the motivation was that
lots of people run with INVARIANTS but no one runs with DIAGNOSTIC.
panic strings needn't and shouldn't have a terminating newline.
Finally, there is one functional change. The sched_pin() in
pmap_remove_pages() is an artifact of the way we temporarily map page
table pages on i386. (The mappings are processor private. We don't do
a system-wide shootdown.) It isn't needed by MIPS.
Tested by: jchandra
Submitted by: alc
9ebbcfd58b