Add some people to rust-lang/rust rotation.

[ehuss]

Per the conversation at https://internals.rust-lang.org/t/highfive-rotation/11865, some people have volunteered to help with reviews.

[ehuss]

Note: I'm a little uncertain about adding cuviper since they aren't currently on rotation for anything, and I don't want to make assumptions for whatever team is responsible for llvm (T-compiler?). cuviper has bors rights via the release team.

I'm only moderately certain things will work correctly for the submodules. I looked through the code and did some simple tests, and it seems like it should work.

cc @Mark-Simulacrum @Centril @joshtriplett @cuviper @petrochenkov

[cuviper]

Note: I'm a little uncertain about adding cuviper since they aren't currently on rotation for anything, and I don't want to make assumptions for whatever team is responsible for llvm (T-compiler?). cuviper has bors rights via the release team.

FWIW, I also have push access to rust-lang/llvm-project already. It would probably be a good idea to add others for LLVM reviews too, if I may volunteer them: @hanna-kruppe, @nagisa, @nikic

[petrochenkov]

The directory list looks seriously outdated.
Perhaps it needs to be regenerated.

[ehuss]

Yea, I had removed them, but decided this PR was pretty long and harder to review. Submitted separately as #251.

[Mark-Simulacrum]

This looks good to me, I'm happy to merge as-is I think -- do you want to merge #251 and then rebase or vice versa?

[ehuss]

Doesn't matter to me. This first, then 251 might be easier to rebase.