syntax: enable attributes and cfg on struct fields
This enables conditional compilation of field initializers in a struct literal, simplifying construction of structs whose fields are themselves conditionally present. For example, the intializer for the constant in the following becomes legal, and has the intuitive effect:
```rust
struct Foo {
#[cfg(unix)]
bar: (),
}
const FOO: Foo = Foo {
#[cfg(unix)]
bar: (),
};
```
It's not clear to me whether this calls for the full RFC process, but the implementation was simple enough that I figured I'd begin the conversation with code.
resolve: clean up the semantics of `self` in an import list
Change `self` in an import list `use foo::bar::{self, ...};` to import `bar` only in the type namespace. Today, `bar` is imported in every namespace in which `foo::bar` is defined.
This is a [breaking-change], see https://github.com/rust-lang/rust/issues/38293#issue-194817974 for examples of code that would break.
Fixes#38293.
r? @nrc
[11/n] Separate ty::Tables into one per each body.
_This is part of a series ([prev](https://github.com/rust-lang/rust/pull/38449) | [next]()) of patches designed to rework rustc into an out-of-order on-demand pipeline model for both better feature support (e.g. [MIR-based](https://github.com/solson/miri) early constant evaluation) and incremental execution of compiler passes (e.g. type-checking), with beneficial consequences to IDE support as well.
If any motivation is unclear, please ask for additional PR description clarifications or code comments._
<hr>
In order to track the results of type-checking and inference for incremental recompilation, they must be stored separately for each function or constant value, instead of lumped together.
These side-`Tables` also have to be tracked by various passes, as they visit through bodies (all of which have `Tables`, even if closures share the ones from their parent functions). This is usually done by switching a `tables` field in an override of `visit_nested_body` before recursing through `visit_body`, to the relevant one and then restoring it - however, in many cases the nesting is unnecessary and creating the visitor for each body in the crate and then visiting that body, would be a much cleaner solution.
To simplify handling of inlined HIR & its side-tables, their `NodeId` remapping and entries HIR map were fully stripped out, which means that `NodeId`s from inlined HIR must not be used where a local `NodeId` is expected. It might be possible to make the nodes (`Expr`, `Block`, `Pat`, etc.) that only show up within a `Body` have IDs that are scoped to that `Body`, which would also allow `Tables` to use `Vec`s.
That last part also fixes#38790 which was accidentally introduced in a previous refactor.
E0088/E0090 fix
This fixes an issue reported by @eddyb (https://github.com/rust-lang/rust/pull/36208#issuecomment-2707092230) where the check for "too few lifetime parameters" was removed in one of the error message PRs.
I also removed the span shrinking from E0088, as early bound lifetimes give you a confusing underline in some cases.
r=eddyb
Dont check stability for items that are not pub to universe.
Dont check stability for items that are not pub to universe.
In other words, skip it for private and even `pub(restricted)` items, because stability checks are only relevant to things visible in other crates.
Fix#38412.
resolve: don't `unused_qualifications`-check global paths
We started `unused_qualifications`-checking global paths in #38014, causing #38682.
Fixes#38682.
r? @nrc
Properly ban the negation of unsigned integers in type-checking.
Lint-time banning of unsigned negation appears to be vestigial from a time it was feature-gated.
But now it always errors and we do have the ability to deref the checking of e.g. `-0`, through the trait obligation fulfillment context, which will only succeed/error when the `0` gets inferred to a specific type.
The two removed tests are the main reason for finally cleaning this up, they need changing all the time when refactoring the HIR-based `rustc_const_eval` and/or `rustc_passes::consts`, as warnings pile up.
