Support for Unicode characters had been added to the keyboard code,
but there are keymaps that have accented characters accessed via dead
key combinations, and those were still restricted to 8 bit codes.
This update to kbd.c adds support for Unicode characters and
compatibility code that allows a kbdcontrol command built from kbio.h
without these patches to work on a new kernel.
Compatibility code that allows a new kbdcontrol binary running on an
old kernel to load and display the dead key map will be committed in a
separate commit.
Reviewed by: imp, brooks
Approved by: brooks
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D38381
4972fb9276