...instead of hand rolling impls, since
1. It's nicer
2. It fixes a buggy `Ord` impl of `SocketAddrV6`, which ignored half of the fields

Note: We do not expect to provide internalizing methods for all
StableMIR constructs. They exist only to help migrating efforts to allow
users to mix StableMIR and internal constructs.

This flag has to be used in combination with `-Zunstable-options`,
and is added in advance of adding branch coverage instrumentation.

…esleywiser

Introduce `-C instrument-coverage=branch` to gate branch coverage

This was extracted from rust-lang#115061 and can land independently from other coverage related work.

The flag is unused for now, but is added in advance of adding branch coverage support.
It is an unstable, nightly only flag that needs to be used in combination with `-Zunstable-options`, like so: `-Zunstable-options -C instrument-coverage=branch`.

The goal is to develop branch coverage as an unstable opt-in feature first, before it matures and can be turned on by default.

…tics-7, r=oli-obk

Migrate diagnostics in `rustc_hir_analysis/src/coherence/orphan.rs`

r? ``@compiler-errors``

…shtriplett

Derive `Ord`, `PartialOrd` and `Hash` for `SocketAddr*`

Fixes rust-lang#116711

The main pain of this PR is to fix the buggy impl of `Ord` for `SocketAddrV6`, which ignored half of the fields (while `PartialEq` is derived):
https://github.com/rust-lang/rust/blob/4603f0b8afb495ae56cd4c8f70d5d478d906ac54/library/core/src/net/socket_addr.rs#L99-L106

https://github.com/rust-lang/rust/blob/4603f0b8afb495ae56cd4c8f70d5d478d906ac54/library/core/src/net/socket_addr.rs#L676

For me it looks like a simple copy-paste error made in rust-lang#72239 (copy from v4 impl) (cc `@hch12907),` as I don't see this behavior being mentioned anywhere on the PR and it also does not respect `cmp` trait "rules". I also do not see any reasons for those impls to _not_ be derived.

It's a shame we did not notice this for 28 versions/3 years. I guess this is a bug fix, but I'm not sure what the process here should be.

r? libs

Avoid unnecessary renumbering during borrowck

Currently, after renumbering there are always unused `RegionVid`s if the return type contains any regions, this is due to `visit_ty` being called twice on the same `Ty`: once with `TyContext::ReturnTy` and once with `TyContext::LocalDecl { local: _0 }`. This PR skips renumbering the first time around.

…xpect, r=b-naber

Suggest unwrap/expect for let binding type mismatch

Found it when investigating rust-lang#116738
I'm not sure whether it's a good style to suggest `unwrap`, seems it's may helpful for newcomers.

rust-lang#116738 needs another fix to improve it.

Add target features for LoongArch

Add method to convert internal to stable constructs

This is an alternative implementation to rust-lang#116999. I believe we can still improve the logic a bit here, but I wanted to see which direction we should go first.

In this implementation, the API is simpler and we keep Tables somewhat private. The definition is still public though, since we have to expose the Stable trait. However, there's a cost of keeping another thread-local and using `Rc`, but I'm hoping it will be a small cost.

r? ``@oli-obk``
r? ``@spastorino``

Remove `#[allow(incomplete_features)]` from RPITIT/AFIT tests

They've been unnecessary for a while.