so that it is possible for kdump and truss to include them both. Use
#defines from pcvt_ioctl.h in conflicting cases, since pcvt_ioctl.h
gives a hint about the bogus third arg to _IO(). Ifdef the common
typedefs. Export `struct key_t' from pcvt_ioctl.h so pcvt_ioctl.h is
bug for bug compatible with console.h (now both are broken in C++
mode).
- don't include <sys/ioctl.h> in any header. Include <sys/ioccom.h>
instead. This was already done in 4.4Lite for the most important
ioctl headers. Header spam currently increases kernel build
times by 10-20%. There are more than 30000 #includes (not counting
duplicates) for compiling LINT.
- include <sys/types.h> if and only it is necessary to make the header
almost self-sufficient (some ioctl headers still need structs from
elsewhere).
- uniformized idempotency ifdefs. Copied the style in the 4.4Lite
ioctl headers.
