Test that System.exitWith doesn't kill the interpreter
--- /dev/null
+-- bug: shouldn't kill the whole system
+System.exitFailure
--- /dev/null
+ ___ ___ _
+ / _ \ /\ /\/ __(_)
+ / /_\// /_/ / / | | GHC Interactive, version 5.01, for Haskell 98.
+/ /_\\/ __ / /___| | http://www.haskell.org/ghc/
+\____/\/ /_/\____/|_| Type :? for help.
+
+Loading package std ... linking ... done.
+Prelude> -- bug: shouldn't kill the whole system
+Prelude> System.exitFailure
+*** Exception: exit: ExitFailure 1
+Prelude> Leaving GHCi.