Move riscv-macros to root directory

[romancardenas]

The idea is trying to sanitize the procedural macros crates that we have (namely, riscv-macros and riscv-rt-macros). Now that riscv-macros has a rt feature, I think it would make sense to merge both crates and try to reuse utility parts such as all the code that adapts to the final target.

[rmsyn]

The idea is trying to sanitize the procedural macros crates that we have (namely, riscv-macros and riscv-rt-macros). Now that riscv-macros has a rt feature, I think it would make sense to merge both crates and try to reuse utility parts such as all the code that adapts to the final target.

It looks like you've only moved over the riscv/macros so far. Are you planning to bring in the riscv-rt/macros stuff as well? Maybe feature-gated behind the rt feature?

For the stuff brought over from riscv/macros it might also make sense to put it behind a #[cfg(not(feature = "rt"))] (or introduce a new feature), to avoid bringing in stuff that the riscv-rt crate doesn't use. Not sure how it would affect things, since these are proc-macros, and I'm assuming what doesn't get used doesn't get compiled in. So, maybe a bit of overengineering.

[romancardenas]

@rmsyn yes, in a set of future PRs I will try to merge both crates wisely. Regarding things in riscv-macros that are not used by riscv-rt, riscv-rt depends on riscv, so I guess it shouldn't be a problem.

[romancardenas]

Hopefully, this PR fixes the CI for all the subsequent PRs