refactor(core): Add gr_user_break syscall to replace all non returning syscalls.

[mqxf]

Resolves #3216

@reviewer-or-team

[breathx]

First of all, the issue is already solved. No idea why GitHub shows only reference.
Secondly, you can't just remove support for some already existing on-chain calls

[mqxf]

The issue wasn't solved, since he mentioned two syscalls, gr_system_break, which was solved, and gr_user_break, which wasn't. I asked around before making this issue and I am not removing any support, we are just moving any syscalls that dont return into one syscall, since they don't take many arguments.

[breathx]

The issue wasn't solved, since he mentioned two syscalls, gr_system_break, which was solved, and gr_user_break, which wasn't.

#3512 (review) It was discussed that other changes are redundant and incorrect.

I asked around before making this issue and I am not removing any support, we are just moving any syscalls that dont return into one syscall, since they don't take many arguments.

As I can see, you've removed support for previously existing programs, because old signatures of syscalls no longer exist.

[mqxf]

I see. A bit of a stretch, but if this is useful enough, could some sort of "migrations" be used, where when a program is loaded, I could write some code which would check if it imports syscalls and replace the uses of those syscalls with the new break syscall? Probably not, but just an idea.