test case for a799c7b28e3590a00b2d915035649fc9b8ac737b

[Nikodemus Siivola]

Bug fixed in a799c7b28e3590a00b2d915035649fc9b8ac737b doesn't have a test-case.

Nikodemus thinks what needs to be done is to construct an SBCL process that is a session leader without a controlling terminal, which then tries the

  (process-close (run-program "cat" () :pty t :search t :wait nil))

thing -- which before the fixed used to make the first pty the controlling terminal of the process, causing a SIGHUP with the master-fd is closed.