improve an enum
revert "cap builtin updates"

this reverts commit e1b3f1fb798de7edc7a0c10ca65dbf18f04f5113.
cap builtin updates
make use of types::c for stdint.h types
update for char removal
make buffer.data nullable
more type improvements
add stdint.ha for other arches

copied in mrsh's license cause this was literally just a few hours of
sed scripting on mrsh/*.h
improve mapping from c to hare types