Uplift more query stuff
- Uplift various query input/response internals
- Uplift the `ProofTree` structures and make the `ProofTreeBuilder` stuff (mostly) generic over `Interner`
- Stop using `TyCtxt::def_kind` in favor of `AliasTerm::kind`
r? lcnr
Only make GAT ambiguous in `match_projection_projections` considering shallow resolvability
In #123537, I tweaked the hack from #93892 to use `resolve_vars_if_possible` instead of `shallow_resolve`. This considers more inference guidance ambiguous. This resulted in crater regressions in #125196.
I've effectively reverted the change to the old behavior. That being said, I don't *like* this behavior, but I'd rather keep it for now since #123537 was not meant to make any behavioral changes. See the attached example.
This also affects the new solver, for the record, which doesn't have any rules about not guiding inference from param-env candidates which may constrain GAT args as a side-effect.
r? `@lcnr` or `@jackh726`
Rename Unsafe to Safety
Alternative to #124455, which is to just have one Safety enum to use everywhere, this opens the posibility of adding `ast::Safety::Safe` that's useful for unsafe extern blocks.
This leaves us today with:
```rust
enum ast::Safety {
Unsafe(Span),
Default,
// Safe (going to be added for unsafe extern blocks)
}
enum hir::Safety {
Unsafe,
Safe,
}
```
We would convert from `ast::Safety::Default` into the right Safety level according the context.
Split out `ty::AliasTerm` from `ty::AliasTy`
Splitting out `AliasTerm` (for use in project and normalizes goals) and `AliasTy` (for use in `ty::Alias`)
r? lcnr
solve: all "non-structural" logging to trace
This enables us to start with `RUSTC_LOG=rustc_trait_selection::solve=debug` to figure out *where* something went wrong, to then separately use `trace` to get to the details.
r? ``@compiler-errors``
Eliminate some `FIXME(lcnr)` comments
In some cases this involved changing code. In some cases the comment was able to removed or replaced.
r? ``@lcnr``
`InferCtxt::next_{ty,const}_var*` all take an origin, but the
`param_def_id` is almost always `None`. This commit changes them to just
take a `Span` and build the origin within the method, and adds new
methods for the rare cases where `param_def_id` might not be `None`.
This avoids a lot of tedious origin building.
Specifically:
- next_ty_var{,_id_in_universe,_in_universe}: now take `Span` instead of
`TypeVariableOrigin`
- next_ty_var_with_origin: added
- next_const_var{,_in_universe}: takes Span instead of ConstVariableOrigin
- next_const_var_with_origin: added
- next_region_var, next_region_var_in_universe: these are unchanged,
still take RegionVariableOrigin
The API inconsistency (ty/const vs region) seems worth it for the
large conciseness improvements.
