Make the GATS self outlives error take into GATs in the inputs
Before, the reasoning was that outlives should factor in to the outlives error, because that value is produced and inputs aren't. However, this is potentially confusing, and we can just require this for now and relax it later if we need. GATs in where clauses still don't count for the self outlives error, and I've added a test for that.
This now errors:
```rust
trait Input {
type Item<'a>;
//~^ missing required
fn takes_item<'a>(&'a self, item: Self::Item<'a>);
}
```
I've also added a test that this does not:
```rust
trait WhereClause {
type Item<'a>;
fn takes_item<'a>(&'a self) where Self::Item<'a>: ;
}
```
r? ``@compiler-errors``
UnreachableProp: Preserve unreachable branches for multiple targets
Before, UnreachablePropagation removed all unreachable branches. This was a pessimization, as it removed information about reachability that was used later in the optimization pipeline.
For example, this code
```rust
pub enum Two { A, B }
pub fn identity(x: Two) -> Two {
match x {
Two::A => Two::A,
Two::B => Two::B,
}
}
```
basically has `switchInt() -> [0: 0, 1: 1, otherwise: unreachable]` for the match. This allows it to be transformed into a simple `x`. If we remove the unreachable branch, the transformation becomes illegal.
This was the problem keeping `UnreachablePropagation` from being enabled, so we can enable it now.
Something similar already happened in #77800, but it did not show a perf improvement there. Let's try it again anyways!
Fixes#68105, although that issue has been fixed for a long time (see #77680).
Convert diagnostics in parser/expr to SessionDiagnostic
This migrates all the easy cases in `rustc_parse::parser::expr` to `SessionDiagnostic`s, I've left things such as `multipart_suggestion`s out for now in the hopes of a derive API being developed soon.
Expand potential inner `Or` pattern for THIR
Code assumed there wouldn't be a deeper `Or` pattern inside expanded `PatStack` this fixes it by looking for the `Or` pattern inside expanded `PatStack`.
A more ideal solution would be recursively doing this but I haven't found a good way to do that.
_fixes #97898_
Show absolute line numbers if span is outside relative span
In the MIR pretty printing, it can sometimes happen that the span of the statement is outside the span of the body (for example through inlining). In this case, don't display a relative span but an absolute span. This will make the mir-opt-tests a little more prone to diffs again, but the impact should be small.
Fixes#99854
r? `@oli-obk`
