Design Draf: Allow to annotate code as must-not-allocate

[adelarsq]

It's an interesting idea based on the article https://notes.eatonphil.com/2024-03-15-zig-rust-and-other-languages.html :

I think the ideal situation in the future will be that every language supports annotating blocks of code as must-not-allocate or something along those lines. Either the compiler will enforce this and fail if you seem to allocate in a block marked must-not-allocate, or it will panic during runtime so you can catch this in tests.