…eexport

…xports

The check within changed from `delay_span_bug` to `delay_good_path_bug`
in rust-lang#110476, and removing the check altogether was considered. It's a
very weak sanity check and gets in the way of removing good path delayed
bugs altogether, so this PR just removes it.

It's only has a single remaining purpose: to ensure that a diagnostic is
printed when `trimmed_def_paths` is used. It's an annoying mechanism:
weak, with odd semantics, badly named, and gets in the way of other
changes.

This commit replaces it with a simpler `must_produce_diag` mechanism,
getting rid of a diagnostic `Level` along the way.

with this, alias-relate treats all aliases the same way
and it can be used for structural normalization.

Swapping the direction of this merge produces the same results, but means that
we never need to mutate `curr`.

Now that we never mutate `curr.span`, we don't need to store its original span
separately.

This requires some extra boilerplate, but in exchange it becomes much easier to
see how each field and method is actually used.

Now that `prev` has its own dedicated struct, we can store the original span in
that struct, instead of in a separate field in the refiner.

If we only check for duplicate spans when `prev` is unmodified, we reduce the
number of situations that `update_pending_dups` needs to handle.

This could potentially change the coverage spans we produce in some unknown
corner cases, but none of our current coverage tests indicate any change.

unstable-book: add quick-edit link

…erge, r=GuillaumeGomez

rustdoc: Fix handling of doc_auto_cfg feature for cfg attributes on glob reexport

This is a follow-up of rust-lang#120501 and a part of rust-lang#120487.

r? `@notriddle`

modify alias-relate to also normalize ambiguous opaques

allows a bunch of further cleanups and generally simplifies the type system. To handle rust-lang/trait-system-refactor-initiative#8 we'll have to add a some additional complexity to the `(Alias, Infer)` branches in alias-relate, so removing the opaque type special case here is really valuable.

It does worsen `deduce_closure_signature` and friends even more as they now receive an inference variable which is only constrained via an `AliasRelate` goal. These probably have to look into alias relate goals somehow. Leaving that for a future PR as this is something we'll have to tackle regardless.

r? `@compiler-errors`

Remove good path delayed bugs

Because they're not that useful, and kind of annoying. Details in the individual commits.

r? ```@compiler-errors```

…sper

match lowering: simplify block creation

Match lowering was doing complicated things with block creation. As far as I can tell it was trying to avoid creating unneeded blocks, but of the three places that start out with `otherwise = &mut None`, two of them called `otherwise.unwrap_or_else(|| self.cfg.start_new_block())` anyway. As far as I can tell the only place where this PR makes a difference is in `lower_match_tree`, which did indeed sometimes avoid creating the unreachable final block + FakeRead. Unless this is important I propose we do the naive thing instead.

I have not checked all the graph isomorphisms by hand, but at a glance the test diff looks sensible.

r? `@matthewjasper`

coverage: Simplify some parts of the coverage span refiner

This is another incremental step on my quest to dismantle the coverage span refiner into something more understandable and maintainable.

The biggest change here is splitting up `CoverageSpan` into several more specific structs. Doing so reveals that most of the places that were using that struct only need a subset of its fields and methods.

We can also get rid of separate tracking of `curr_original_span` and `prev_original_span`, by observing that `curr.span` never actually needs to be mutated, and that we can store `prev_original_span` directly in the dedicated struct for `prev`.

`@rustbot` label +A-code-coverage

…nk-chapter, r=notriddle

Extend intra-doc link chapter in the rustdoc book

Linked to rust-lang#117178.

r? `@notriddle`

RustWrapper: adapt for coverage mapping API changes

There've been a number of changes to the coverage mapping API today, but the end result is that specifying the MCDC parameters is now optional (they've been moved to the end of the argument list and now default to `std::monostate`).

`@rustbot` label: +llvm-main

r? `@durin42`