MFC 239512:
Add a BUS_CHILD_DELETED() method that a bus can hook to allow it to cleanup
any bus-specific state (such as ivars) when a child device is deleted.
MFC 240467:
Ignore stop and continue signals sent to an exiting process.  Stop signals
set p_xstat to the signal that triggered the stop, but p_xstat is also
used to hold the exit status of an exiting process.  Without this change,
a stop signal that arrived after a process was marked P_WEXIT but before
it was marked a zombie would overwrite the exit status with the stop signal
number.
MFC 240473:
Add some registers defined in PCI 3.0 including new AER bits.
Fix the build.

Back out mis-guided compat shim that should not have been MFC'ed
MFC r247034:
  Check if the -sec option is given without an argument.

PR:		bin/170413
Submitted by:	Andrey Simonenko <simon@comsys.ntu-kpi.kiev.ua>