…r arg

…ency and we have a trait error

…th no default method body

Co-authored-by: David Tolnay <dtolnay@gmail.com>

On LLVM 20, these instructions already get eliminated, which at least
partially satisfies a TODO. I'm not talented enough at using FileCheck
to try and constrain this further, but if we really want to we could
copy an LLVM 20 specific version of this test that would restore it to
being CHECK-NEXT: insertvalue ...

@rustbot label: +llvm-main

…DefKind::SyntheticCoroutineBody

This makes it much clearer which things are used outside the crate.

Reflow overly long comments, plus some minor whitespace improvements.

Because `bx` contains a `cx`.

`'mir` is not a good lifetime name in `LocalAnalyzer`, because it's used
on two unrelated fields. `'a` is more standard for a situation like this
(e.g. rust-lang#130022).

…option, r=jieyouxu

Fix rust-lang#128930: Print documentation of CLI options missing their arg

Fix rust-lang#128930. Failing to give an argument to CLI options which require it now prints something like:
```
$ rustc --print
error: Argument to option 'print' missing
       Usage:
           --print [crate-name|file-names|sysroot|target-libdir|cfg|check-cfg|calling-conventions|target-list|target-cpus|target-features|relocation-models|code-models|tls-models|target-spec-json|all-target-specs-json|native-static-libs|stack-protector-strategies|link-args|deployment-target]
                               Compiler information to print on stdout
```

… r=lcnr

Relate receiver invariantly in method probe for `Mode::Path`

Effectively reverts part of rust-lang#126128
Fixes rust-lang#126227

This PR changes method probing to use equality for fully path-based method lookup, and subtyping for receiver `.` method lookup.

r? lcnr

… r=dtolnay

Add new_cyclic_in for Rc and Arc

Currently, new_cyclic_in does not exist for Rc and Arc. This is an oversight according to rust-lang/wg-allocators#132.

This PR adds new_cyclic_in for Rc and Arc. The implementation is almost the exact same as new_cyclic with some small differences to make it allocator-specific. new_cyclic's implementation has been replaced with a call to `new_cyclic_in(data_fn, Global)`.

Remaining questions:
* ~~Is requiring Allocator to be Clone OK? According to rust-lang/wg-allocators#88, Allocators should be cheap to clone. I'm just hesitant to add unnecessary constraints, though I don't see an obvious workaround for this function since many called functions in new_cyclic_in expect an owned Allocator. I see Allocator.by_ref() as an option, but that doesn't work on when creating Weak { ptr: init_ptr, alloc: alloc.clone() }, because the type of Weak then becomes Weak<T, &A> which is incompatible.~~ Fixed, thank you `@zakarumych!` This PR no longer requires the allocator to be Clone.
* Currently, new_cyclic_in's documentation is almost entirely copy-pasted from new_cyclic, with minor tweaks to make it more accurate (e.g. Rc<T> -> Rc<T, A>). The example section is removed to mitigate redundancy and instead redirects to cyclic_in. Is this appropriate?
* ~~The comments in new_cyclic_in (and much of the implementation) are also copy-pasted from new_cyclic. Would it be better to make a helper method new_cyclic_in_internal that both functions call, with either Global or the custom allocator? I'm not sure if that's even possible, since the internal method would have to return Arc<T, Global> and I don't know if it's possible to "downcast" that to an Arc<T>. Maybe transmute would work here?~~ Done, thanks `@zakarumych`
* Arc::new_cyclic is #[inline], but Rc::new_cyclic is not. Which is preferred?
* nit: does it matter where in the impl block new_cyclic_in is defined?

…body, r=lcnr

Encode `coroutine_by_move_body_def_id` in crate metadata

We synthesize the MIR for a by-move body for the `FnOnce` implementation of async closures. It can be accessed with the `coroutine_by_move_body_def_id` query. We weren't encoding this query in the metadata though, nor were we properly recording that synthetic MIR in `mir_keys`, so the `optimized_mir` wasn't getting encoded either!

Stacked on top is a fix to consider `DefKind::SyntheticCoroutineBody` to return true in several places I missed. Specifically, we should consider the def-kind in `fn DefKind::is_fn_like()`, since that's what we were using to make sure we ensure `query mir_inliner_callees` before the MIR gets stolen for the body. This led to some CI failures that were caught by miri but which I added a test for.

Don't call `extern_crate` when local crate name is the same as a dependency and we have a trait error

rust-lang#124944 implemented logic to point out when a trait bound failure involves a *trait* and *type* who come from identically named but different crates. This logic calls the `extern_crate` query which is not valid on `LOCAL_CRATE` cnum, so let's filter that out eagerly.

Fixes rust-lang#130272
Fixes rust-lang#129184

…en, r=jieyouxu

Don't ICE in `opaque_hidden_inferred_bound` lint for RPITIT in trait with no default method body

Inline comment should explain the fix.

Fixes rust-lang#130422

…jubilee

tests: allow trunc/select instructions to be missing

On LLVM 20, these instructions already get eliminated, which at least partially satisfies a TODO. I'm not talented enough at using FileCheck to try and constrain this further, but if we really want to we could copy an LLVM 20 specific version of this test that would restore it to being CHECK-NEXT: insertvalue ...

`@rustbot` label: +llvm-main
r? `@DianQK`

…nups, r=jieyouxu

`rustc_codegen_ssa` cleanups

Just some minor improvements I found while reading through this code.

r? `@jieyouxu`