samples: Add apps/pipes.jakt

[Lenart12]

Simple project using inline cpp and system calls to demonstrate pipe, fork and dup2.

[Lenart12]

Changed commit message and implemented changes mentioned in the review. Some weird arithmetic which I don't like was needed because negated c_int needs to be fixed (to avoid things like not (close_ret >= 0), close_ret == -1 would be better!).

[Lenart12]

Sorry this is taking so long, english is not my strong suit :( Unsafe was done like that before because if I had two unsafe blocks the char buffer wouldnt be defined in the second block but I have refactored it so there is only one now.

[stale[bot]]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed in 7 days if no further activity occurs. Thank you for your contributions!

[stale[bot]]

This pull request has been closed because it has not had recent activity. Feel free to re-open if you wish to still contribute these changes. Thank you for your contributions!