Added stubs for homebrew

[psxdev]

We need it to properly use with homebrew

TODO incorporate all entries in all sprx stubs

[masterzorag]

If I just declare struct knote in my sample, this header give me error due forwarding declaration of struct knote;
Also, ps4sdk-examples/posix/stdio-redirect need 1 line change to compile fine now;

[hitodama]

Hi @masterzorag! Thanks for the feedback and help! The example can be fixed by adding #define __BSD_VISIBLE 1 before the includes.

But I would like to avoid including this header into the user-space as well. Instead of adding the include, can we use a void pointer to define SceKernelEvent? I see getter symbols for the fields of the structs, which suggests that this is the intended way of using the type. E.g. sceKernelGetEventData: SceKernelEvent -> intptr_t.

So, I would remove the sys/event.h include and use typedef void * SceKernelEvent instead. Then add the additional getters like sceKernelGetEventData

[hitodama]

@psxdev if you can fix the above issue I will merge the PR. Alternatively we can close it and you could add it to the libs directly (but there it should not be in /include/sce but in /include) so you will have to refactor your code. If that is ok we can close the PR - otherwise lets add the headers (after the fix above) so that for now you do not need to port your code to the new header locations.