MFC r250849:
Add ddb command 'show pginfo'.
MFC r250850:
Add amd64-specific ddb command 'show phys2dmap'.
MFC r250851:
Fix the hardware watchpoints on SMP amd64.
MFC r250853:
Fix the wait6(2) on 32bit architectures and for the compat32, by using
the right type for the argument in syscalls.master.  Also fix the
posix_fallocate(2) and posix_fadvise(2) compat32 syscalls on the
architectures which require padding of the 64bit argument.
Regenerate.