llgs Linux is no longer doing the translation to some gdb fixed signal
numbers. This change modifies the test method to take in the signo
expected for a segfault. The debugserver test uses the fixed gdb number,
and everything else uses signal.SIGSEGV for the platform.
Sidenote: I somehow did not see this reported in multicore tests.
I will need to verify that we aren't missing test failures in that
script. I need to verify why this wasn't more obvious with
test/dosep.py.
llvm-svn: 216770