MFC r305483,r306030,r306031,r306033,r306036:

r305483:

Fix tests/sys/kqueue NetBSD tests on 32-bit platforms by using proper
format specifier for pointers when printing them out with printf(3)

Pointyhat to: ngie

r306030:

Port vnode_leak_test:main to FreeBSD

Use a simpler way of dumping kern.maxvnodes, i.e. sysctl -n kern.maxvnodes

The awk filtering method employed in NetBSD doesn't work on FreeBSD

r306031:

Port contrib/netbsd-tests/fs/h_funcs.subr to FreeBSD

Use kldstat -m to determine whether or not a filesystem is loaded. This works
well with tmpfs, ufs, and zfs

r306033:

Port sizes_test and statvfs_test to FreeBSD

Similar to r306030, use a simpler method for getting the value of
hw.pagesize, i.e. sysctl -n hw.pagesize. The awk filtering method doesn't
work on FreeBSD

r306036:

Port to mknod_test and readdir_test to FreeBSD

The mknod <file> p command doesn't exist on FreeBSD, like on NetBSD. Use
mkfifo instead to create named pipes (FIFOs).