shared/runtime: Set exit code according to the SystemExit exception.

Add abort setup code `nlr_set_abort` to the standard runtime executor.
This makes the standard runtime respond to abort signal without any further
modifications.

- When aborted, the program exits with 137 exit code (configurable, same as
  posix sig abort), to differentiate from a normal shutdown.

- When exited by exception/crash, the program will exit with exit code 1
  (configurable).

- When exited by exception KeyboardInterrupt, the program will exit with
  exit code 130 (configurable, same as posix sig int).

- When exited with a exit code (from Python environment), this code is
  propagated.  When a different object is passed, exit code is set to 1 and
  the value printed, to be consistent with Python docs:
  https://python.readthedocs.io/en/latest/library/exceptions.html#SystemExit

Signed-off-by: John Smith <jsmith@jsmith.cz>

0 files changed, 0 insertions, 0 deletions