Testing tests that call exit()

  $ exit.c.bin --verbose
  [\x1b[0;34m----\x1b[0m] Criterion v2.2.0 (esc)
  [\x1b[0;34m====\x1b[0m] Running \x1b[0;34m3\x1b[0m tests from \x1b[0;33mexit\x1b[0m: (esc)
  [\x1b[0;34mRUN \x1b[0m] exit::expected_exit (esc)
  [\x1b[0;32mPASS\x1b[0m] exit::expected_exit (esc)
  [\x1b[0;34mRUN \x1b[0m] exit::normal (esc)
  [\x1b[0;32mPASS\x1b[0m] exit::normal (esc)
  [\x1b[0;34mRUN \x1b[0m] exit::unexpected_exit (esc)
  [\x1b[0;34m----\x1b[0m] \x1b[0;1mWarning! The test `exit::unexpected_exit` exited during its setup or teardown.\x1b[0m (esc)
  [\x1b[0;34m====\x1b[0m] Running \x1b[0;34m2\x1b[0m tests from \x1b[0;33mexit_with_fixtures\x1b[0m: (esc)
  [\x1b[0;34mRUN \x1b[0m] exit_with_fixtures::fini_exits (esc)
  [\x1b[0;32mPASS\x1b[0m] exit_with_fixtures::fini_exits (esc)
  [\x1b[0;34m----\x1b[0m] \x1b[0;1mWarning! The test `exit_with_fixtures::fini_exits` exited during its setup or teardown.\x1b[0m (esc)
  [\x1b[0;34mRUN \x1b[0m] exit_with_fixtures::init_exits (esc)
  [\x1b[0;34m----\x1b[0m] \x1b[0;1mWarning! The test `exit_with_fixtures::init_exits` exited during its setup or teardown.\x1b[0m (esc)
  [\x1b[0;34m====\x1b[0m] \x1b[0;1mSynthesis: Tested: \x1b[0;34m5\x1b[0;1m | Passing: \x1b[0;32m3\x1b[0;1m | Failing: \x1b[0;31m2\x1b[0;1m | Crashing: \x1b[0;31m2\x1b[0;1m \x1b[0m (esc)

  $ exit.cc.bin --verbose
  [\x1b[0;34m----\x1b[0m] Criterion v2.2.0 (esc)
  [\x1b[0;34m====\x1b[0m] Running \x1b[0;34m3\x1b[0m tests from \x1b[0;33mexit\x1b[0m: (esc)
  [\x1b[0;34mRUN \x1b[0m] exit::expected_exit (esc)
  [\x1b[0;32mPASS\x1b[0m] exit::expected_exit (esc)
  [\x1b[0;34mRUN \x1b[0m] exit::normal (esc)
  [\x1b[0;32mPASS\x1b[0m] exit::normal (esc)
  [\x1b[0;34mRUN \x1b[0m] exit::unexpected_exit (esc)
  [\x1b[0;34m----\x1b[0m] \x1b[0;1mWarning! The test `exit::unexpected_exit` exited during its setup or teardown.\x1b[0m (esc)
  [\x1b[0;34m====\x1b[0m] Running \x1b[0;34m2\x1b[0m tests from \x1b[0;33mexit_with_fixtures\x1b[0m: (esc)
  [\x1b[0;34mRUN \x1b[0m] exit_with_fixtures::fini_exits (esc)
  [\x1b[0;32mPASS\x1b[0m] exit_with_fixtures::fini_exits (esc)
  [\x1b[0;34m----\x1b[0m] \x1b[0;1mWarning! The test `exit_with_fixtures::fini_exits` exited during its setup or teardown.\x1b[0m (esc)
  [\x1b[0;34mRUN \x1b[0m] exit_with_fixtures::init_exits (esc)
  [\x1b[0;34m----\x1b[0m] \x1b[0;1mWarning! The test `exit_with_fixtures::init_exits` exited during its setup or teardown.\x1b[0m (esc)
  [\x1b[0;34m====\x1b[0m] \x1b[0;1mSynthesis: Tested: \x1b[0;34m5\x1b[0;1m | Passing: \x1b[0;32m3\x1b[0;1m | Failing: \x1b[0;31m2\x1b[0;1m | Crashing: \x1b[0;31m2\x1b[0;1m \x1b[0m (esc)