replace int with i32

[kbkpbot]

As vlang/v#25236 may change int a platform dependent 32/64 bit integer, all int from a C program should translate to i32 in v.

[spytheman]

@kbkpbot why did you delete tests/test.c/1.hello.c and tests/test.c/1.hello.out ?

[spytheman]

@kbkpbot I am sorry, but I've reverted the change from this PR, because it caused the tests to fail, as well as the doom translation on the main V repo:

I'll make sure that this repo also has a CI, to prevent this from happening in the future.

After that, we can redo the changes and be sure that they do not break existing code from working.

[spytheman]

It turns out that the already existing CI workflows, disabled themselves, because the previous commit on master was done more than 60 days ago 🤦🏻‍♂️ . It is now running on master again.

[kbkpbot]

Or we need not fix c2v at all.
As at the end of c2v, it will call vfmt to format the code, which can do the int=>i32 there.