Should we really crash on any unexpected signal?
All of the signals we catch are signals for which the default action specified by POSIX is to terminate. In the case of TRAP, SEGV, ILL, BUS we have no choice. That might be true for FPE too but I can't remember; but either way, either the program was expecting an exception and won't get it, or it was going to crash anyway.
In the case of ABRT, QUIT, INT not terminating seems like the wrong thing to do (and we can't handle them the normal way because we don't have a TEB and can't contact the server).
We could potentially ignore USR1 and USR2, but that doesn't seem great for stability. Whatever was sending them had a reason to do so, and isn't going to function correctly.
Perhaps more saliently, we were already crashing on unexpected signals, simply by virtue of trying to access the TEB and then dereferencing it. This patch just makes it more obvious.