<rdar://problem/12602653>

Add unconditional logging messages to every place in debugserver
where we send a SIGKILL signal or do a ptrace PT_KILL call to
terminate the inferior process.  When the debuggee is silently
killed off, the console logging from debugserver can disambiguate
whether debugserver killed off the process because it failed to
completely set it up, becuase it was told to (via the "k" packet),
or if some external daemon killed it.