Add block ioctl support

* block.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* defs.h [LINUX] (block_ioctl): New function.
* ioctl.c (ioctl_decode) [LINUX]: Use it to decode HDIO_* and BLK*
ioctls.
Patch by Jeff Mahoney <jeffm@suse.com>
4 files changed