Move collector to librustc_mir::monomorphize
cc https://github.com/rust-lang/rust/issues/44334 and https://github.com/rust-lang/rust/issues/45276
* I moved the collector to rustc_mir
* I renamed `TransItem` to `MonoItem`. _(I still need to fix up comments and variable names)_
* I got rid of `common.rs` and `monomorphize.rs` from `librustc_trans_utils`. I moved most of the functionality into `TyCtxt`. I realized that the `librustc_trans_utils::common.rs` was just copy pasted from `librustc_trans::common.rs`.
Should I also get rid of the `librustc_trans::common.rs` in this PR? Most of the functionality seems a bit useless, I decided to put some of it into `TyCtxt` but maybe that is not the correct action here.
Should I also get rid of `librustc_trans_utils` completely here? Or should I do it in a separate PR?
rustc: ensure optimized enums have a properly aligned size.
Fixes#46769 by padding the optimized enums wrapping packed data as necessary.
Note that this is not the only way to solve this - on nightly, #46436 makes it easier to fix without adding new padding because of the replacement of `packed` flags with a non-redundant scheme.
But because it can't be backported, the optimal fix will be in a separate nightly-only PR (#46809).
Add lossless debug implementation for unix OsStrs
Fixes#22766
Invalid utf8 byte sequences are replaced with `\xFF` style escape codes, while valid utf8 goes through the normal `Debug` implementation.
This is necessarily different from the windows Debug implementation, which uses `\u{xxxx}` style escape sequences for unpaired surrogates, but both implementations are consistent in that they are both lossless, and display invalid sequences in the way most similar to existing language syntax.
r? @dtolnay
Add sync module to rustc_data_structures
This PR is split out from https://github.com/rust-lang/rust/pull/45912, since github apparently can't handle such large PRs.
r? @arielb1
