This does not (yet) upgrade ./rust-toolchain
The warnings:
* dead_code "field is never read"
* redundant_semicolons "unnecessary trailing semicolon"
* non_fmt_panic "panic message is not a string literal, this is no longer accepted in Rust 2021"
* unstable_name_collisions "a method with this name may be added to the standard library in the future"
* legacy_derive_helpers "derive helper attribute is used before it is introduced" https://github.com/rust-lang/rust/issues/79202
Summary:
This should make it easier to report errors, and also reduce codesize.
The reason this was so generic is that error reporting was unconditionally
enabled and was super-hot, but now that's no longer the case after bug 1452143,
so we can afford the virtual call in the "error reporting enabled" case.
This opens the possibility of simplifying a lot the error setup as well, though
this patch doesn't do it.
Test Plan: No behavior change, so no new tests.
Reviewers: xidorn
Bug #: 1469957
Differential Revision: https://phabricator.services.mozilla.com/D1734
MozReview-Commit-ID: F3wTdhX9MB5
