conversion interprets input bytes as multibyte sequences and displays
printable characters in the area corresponding to their first byte.
The remaining bytes are shown as "**".
Add some constness to avoid some warnings.
Remove use register keyword.
Deal with missing/unneeded extern/prototypes.
Some minor type changes/casts to avoid warnings.
Reviewed by: md5
deprecation warning from the utility and manual page. Since this utility
is required by POSIX, it's not likely to be removed any time soon.
This is leading up to the addition of the P1003.1-2001 -s -A -j -N -t options.
PR: 36783
