- There is no e.g. signal.SIGKILL on windows:

    golang/os/signal_test.py::test_signal_all Traceback (most recent call last):
      File "Z:\home\kirr\src\tools\go\pygo-win\pygolang\golang\os\testprog\signal_test_all.py", line 82, in <module>
        main()
      File "Z:\home\kirr\src\tools\go\pygo-win\pygolang\golang\os\testprog\signal_test_all.py", line 39, in main
        allsigv.remove(syscall.SIGKILL) # SIGKILL/SIGSTOP cannot be caught
    AttributeError: module 'golang.syscall' has no attribute 'SIGKILL'. Did you mean: 'SIGILL'?

  -> filter-out signals conditionally depending on their presence.

- Need to also filter-out SIGILL/SIGABRT because upon reception MSVC
  runtime terminates process.