c3668d3d7c
Make `rustc_on_unimplemented` std-agnostic for `alloc::rc` See https://github.com/rust-lang/rust/issues/112923 Just a few lines related to `alloc:rc` for `Send` and `Sync`. That seems to be all of the `... = "std::..."` issues found, but there a few notes with `std::` inside them still. r? `@WaffleLapkin`