This is the listener's spawned connection, not the listener itself.
(i.e. this is the test runner's receiving side of test event sockets).
A standard socket.error will just issue an INFO statement and continue.
Something other than a socket.error will get an ERROR: printed (and
also continue).
Hopefully this gets us more info and also handles the completely
to-be-expected scenario that the test inferior might go down at
any point.
llvm-svn: 255581