This thing is totally buggy: 'data_len' is modified by the fs, so calling
kmem_free with it while its value has changed since the kmem_alloc is far
from being a good idea.

If the kernel figures out that something mismatches, it will panic
(typically with kernfs).
Reduce resident_count by number of pages, not number of ptes.
Call mutex_destroy() on sc_kqlock in tap_detach(). Found by LOCKDEBUG.
Allow setting of console speed in init.
Use an enum type for PRINTMODE vs. WIDTHMODE. Compiler output diffs have
been checked.
Don't bother using variables whose value is never changed from the
initialization value.
/usr/include/g++/bits/${CONFIG} directories are created independent of
MKGCC, so fix file lists.