1.1 Release

[topecongiro]

Todos for publishing 1.1 via rustup

1. Close Format const generics #3336. I would like to close this issue before releasing 1.1, as it requires updating rustc-ap-* crates.
2. Update the dependency of racer to use the same rustc-ap-* crates as rustfmt
3. Update the dependency of rls to use the racer with the same rustc-ap-* crates as rustfmt
4. Update the submodule in the rustc repository