Keep original literal tokens in AST
The original literal tokens (`token::Lit`) are kept in AST until lowering to HIR.
The tokens are kept together with their lowered "semantic" representation (`ast::LitKind`), so the size of `ast::Lit` is increased (this also increases the size of meta-item structs used for processing built-in attributes).
However, the size of `ast::Expr` stays the same.
The intent is to remove the "semantic" representation from AST eventually and keep literals as tokens until lowering to HIR (at least), and I'm going to work on that, but it would be good to land this sooner to unblock progress on the [lexer refactoring](https://github.com/rust-lang/rust/pull/59706).
Fixes a part of https://github.com/rust-lang/rust/issues/43081 (literal tokens that are passed to proc macros are always precise, including hexadecimal numbers, strings with their original escaping, etc)
Fixes a part of https://github.com/rust-lang/rust/issues/60495 (everything except for proc macro API doesn't need escaping anymore)
This also allows to eliminate a certain hack from the lexer (https://rust-lang.zulipchat.com/#narrow/stream/131828-t-compiler/topic/pretty-printing.20comments/near/165005357).
cc @matklad
Make tests compatible with musl host
As an alternative to passing explicit linker all over the place I could try linking `cc` to musl gcc since this bootstraps itself.
Assigning for discussion:
r? @alexcrichton
Document the order of {Vec,VecDeque,String}::retain
It's natural for `retain` to work in order from beginning to end, but
this wasn't actually documented to be the case. If we actually promise
this, then the caller can do useful things like track the index of each
element being tested, as [discussed in the forum][1]. This is now
documented for `Vec`, `VecDeque`, and `String`.
[1]: https://users.rust-lang.org/t/vec-retain-by-index/27697
`HashMap` and `HashSet` also have `retain`, and the `hashbrown`
implementation does happen to use a plain `iter()` order too, but it's
not certain that this should always be the case for these types.
r? @scottmcm
Remove redundant "let mut" in write_graph_label
Removed the redundant "let mut" in the write_graph_label function (it caused "let mut let mut" for non-user-defined local variables).
impl From<Infallible> for TryFromSliceError
I believe this was missed when TryFrom was stabilized. I think `TryFromSliceError` and `TryFromIntError` are the only two `TryFrom` error types that appear in `std`. I think trait implementations have to be insta-stable, but I'm not sure.
Rollup of 6 pull requests
Successful merges:
- #60529 (RFC 2008: Uninhabitedness fixes for enum variants and tests)
- #60620 (Fix a couple of FIXMEs in ext::tt::transcribe)
- #60659 (Tweak `Symbol` and `InternedString`)
- #60692 (Extend #60676 test for nested mut patterns.)
- #60697 (add regression test for #60629)
- #60701 (Update mailmap for mati865)
Failed merges:
r? @ghost
