trait_selection: Keep type-op region constraints in borrowck - #161423

Keep rust-lang#158588 focused on reporting solver region constraints. The type-op behavior and its borrowck coverage now live in rust-lang#161423.

…tions_binders_diagnostics, r=BoxyUwU

trait_selection: fix assumptions-on-binders diagnostics

fixes rust-lang#157732

`-Zassumptions-on-binders` was losing the origin of solver region constraints. By the time regionck or borrowck reported them, every constraint received the containing item span, so diagnostics pointed at an entire function or const. Some paths were also still emitting placeholder text (`:3` and `meoow :c`).

This keeps canonical solver responses and `ExternalConstraintsData` span-free, so source locations do not participate in candidate equality or caching. When a response is applied, `EvalCtxt::origin_span` is attached to each atomic solver `RegionConstraint` stored in `InferCtxt`. Late region conversion then uses the span attached to each constraint, including for ambiguity diagnostics.

The affected paths now report `higher-ranked lifetime bound could not be satisfied` at the type use that introduced the failing constraint. UI coverage checks the rust-lang#157732 call-site diagnostic and the existing regionck alias-outlives case. Unit coverage checks that the spanned evaluator stays in semantic parity with the type-ir evaluator and preserves the first ambiguity origin span.

The type-op behavior I ran into while working on this is split into rust-lang#161423.

Future work: carry the failed outlives predicate or originating binder far enough through this path to name the exact bound that failed, rather than only pointing at its origin.

…tions_binders_diagnostics, r=BoxyUwU

trait_selection: fix assumptions-on-binders diagnostics

fixes rust-lang#157732

`-Zassumptions-on-binders` was losing the origin of solver region constraints. By the time regionck or borrowck reported them, every constraint received the containing item span, so diagnostics pointed at an entire function or const. Some paths were also still emitting placeholder text (`:3` and `meoow :c`).

This keeps canonical solver responses and `ExternalConstraintsData` span-free, so source locations do not participate in candidate equality or caching. When a response is applied, `EvalCtxt::origin_span` is attached to each atomic solver `RegionConstraint` stored in `InferCtxt`. Late region conversion then uses the span attached to each constraint, including for ambiguity diagnostics.

The affected paths now report `higher-ranked lifetime bound could not be satisfied` at the type use that introduced the failing constraint. UI coverage checks the rust-lang#157732 call-site diagnostic and the existing regionck alias-outlives case. Unit coverage checks that the spanned evaluator stays in semantic parity with the type-ir evaluator and preserves the first ambiguity origin span.

The type-op behavior I ran into while working on this is split into rust-lang#161423.

Future work: carry the failed outlives predicate or originating binder far enough through this path to name the exact bound that failed, rather than only pointing at its origin.

…tions_binders_diagnostics, r=BoxyUwU

trait_selection: fix assumptions-on-binders diagnostics

fixes rust-lang#157732

`-Zassumptions-on-binders` was losing the origin of solver region constraints. By the time regionck or borrowck reported them, every constraint received the containing item span, so diagnostics pointed at an entire function or const. Some paths were also still emitting placeholder text (`:3` and `meoow :c`).

This keeps canonical solver responses and `ExternalConstraintsData` span-free, so source locations do not participate in candidate equality or caching. When a response is applied, `EvalCtxt::origin_span` is attached to each atomic solver `RegionConstraint` stored in `InferCtxt`. Late region conversion then uses the span attached to each constraint, including for ambiguity diagnostics.

The affected paths now report `higher-ranked lifetime bound could not be satisfied` at the type use that introduced the failing constraint. UI coverage checks the rust-lang#157732 call-site diagnostic and the existing regionck alias-outlives case. Unit coverage checks that the spanned evaluator stays in semantic parity with the type-ir evaluator and preserves the first ambiguity origin span.

The type-op behavior I ran into while working on this is split into rust-lang#161423.

Future work: carry the failed outlives predicate or originating binder far enough through this path to name the exact bound that failed, rather than only pointing at its origin.

…tions_binders_diagnostics, r=BoxyUwU

trait_selection: fix assumptions-on-binders diagnostics

fixes rust-lang#157732

`-Zassumptions-on-binders` was losing the origin of solver region constraints. By the time regionck or borrowck reported them, every constraint received the containing item span, so diagnostics pointed at an entire function or const. Some paths were also still emitting placeholder text (`:3` and `meoow :c`).

This keeps canonical solver responses and `ExternalConstraintsData` span-free, so source locations do not participate in candidate equality or caching. When a response is applied, `EvalCtxt::origin_span` is attached to each atomic solver `RegionConstraint` stored in `InferCtxt`. Late region conversion then uses the span attached to each constraint, including for ambiguity diagnostics.

The affected paths now report `higher-ranked lifetime bound could not be satisfied` at the type use that introduced the failing constraint. UI coverage checks the rust-lang#157732 call-site diagnostic and the existing regionck alias-outlives case. Unit coverage checks that the spanned evaluator stays in semantic parity with the type-ir evaluator and preserves the first ambiguity origin span.

The type-op behavior I ran into while working on this is split into rust-lang#161423.

Future work: carry the failed outlives predicate or originating binder far enough through this path to name the exact bound that failed, rather than only pointing at its origin.

…tions_binders_diagnostics, r=BoxyUwU

trait_selection: fix assumptions-on-binders diagnostics

fixes rust-lang#157732

`-Zassumptions-on-binders` was losing the origin of solver region constraints. By the time regionck or borrowck reported them, every constraint received the containing item span, so diagnostics pointed at an entire function or const. Some paths were also still emitting placeholder text (`:3` and `meoow :c`).

This keeps canonical solver responses and `ExternalConstraintsData` span-free, so source locations do not participate in candidate equality or caching. When a response is applied, `EvalCtxt::origin_span` is attached to each atomic solver `RegionConstraint` stored in `InferCtxt`. Late region conversion then uses the span attached to each constraint, including for ambiguity diagnostics.

The affected paths now report `higher-ranked lifetime bound could not be satisfied` at the type use that introduced the failing constraint. UI coverage checks the rust-lang#157732 call-site diagnostic and the existing regionck alias-outlives case. Unit coverage checks that the spanned evaluator stays in semantic parity with the type-ir evaluator and preserves the first ambiguity origin span.

The type-op behavior I ran into while working on this is split into rust-lang#161423.

Future work: carry the failed outlives predicate or originating binder far enough through this path to name the exact bound that failed, rather than only pointing at its origin.

…tions_binders_diagnostics, r=BoxyUwU

trait_selection: fix assumptions-on-binders diagnostics

fixes rust-lang#157732

`-Zassumptions-on-binders` was losing the origin of solver region constraints. By the time regionck or borrowck reported them, every constraint received the containing item span, so diagnostics pointed at an entire function or const. Some paths were also still emitting placeholder text (`:3` and `meoow :c`).

This keeps canonical solver responses and `ExternalConstraintsData` span-free, so source locations do not participate in candidate equality or caching. When a response is applied, `EvalCtxt::origin_span` is attached to each atomic solver `RegionConstraint` stored in `InferCtxt`. Late region conversion then uses the span attached to each constraint, including for ambiguity diagnostics.

The affected paths now report `higher-ranked lifetime bound could not be satisfied` at the type use that introduced the failing constraint. UI coverage checks the rust-lang#157732 call-site diagnostic and the existing regionck alias-outlives case. Unit coverage checks that the spanned evaluator stays in semantic parity with the type-ir evaluator and preserves the first ambiguity origin span.

The type-op behavior I ran into while working on this is split into rust-lang#161423.

Future work: carry the failed outlives predicate or originating binder far enough through this path to name the exact bound that failed, rather than only pointing at its origin.

…tions_binders_diagnostics, r=BoxyUwU

trait_selection: fix assumptions-on-binders diagnostics

fixes rust-lang#157732

`-Zassumptions-on-binders` was losing the origin of solver region constraints. By the time regionck or borrowck reported them, every constraint received the containing item span, so diagnostics pointed at an entire function or const. Some paths were also still emitting placeholder text (`:3` and `meoow :c`).

This keeps canonical solver responses and `ExternalConstraintsData` span-free, so source locations do not participate in candidate equality or caching. When a response is applied, `EvalCtxt::origin_span` is attached to each atomic solver `RegionConstraint` stored in `InferCtxt`. Late region conversion then uses the span attached to each constraint, including for ambiguity diagnostics.

The affected paths now report `higher-ranked lifetime bound could not be satisfied` at the type use that introduced the failing constraint. UI coverage checks the rust-lang#157732 call-site diagnostic and the existing regionck alias-outlives case. Unit coverage checks that the spanned evaluator stays in semantic parity with the type-ir evaluator and preserves the first ambiguity origin span.

The type-op behavior I ran into while working on this is split into rust-lang#161423.

Future work: carry the failed outlives predicate or originating binder far enough through this path to name the exact bound that failed, rather than only pointing at its origin.

…tions_binders_diagnostics, r=BoxyUwU

trait_selection: fix assumptions-on-binders diagnostics

fixes rust-lang#157732

`-Zassumptions-on-binders` was losing the origin of solver region constraints. By the time regionck or borrowck reported them, every constraint received the containing item span, so diagnostics pointed at an entire function or const. Some paths were also still emitting placeholder text (`:3` and `meoow :c`).

This keeps canonical solver responses and `ExternalConstraintsData` span-free, so source locations do not participate in candidate equality or caching. When a response is applied, `EvalCtxt::origin_span` is attached to each atomic solver `RegionConstraint` stored in `InferCtxt`. Late region conversion then uses the span attached to each constraint, including for ambiguity diagnostics.

The affected paths now report `higher-ranked lifetime bound could not be satisfied` at the type use that introduced the failing constraint. UI coverage checks the rust-lang#157732 call-site diagnostic and the existing regionck alias-outlives case. Unit coverage checks that the spanned evaluator stays in semantic parity with the type-ir evaluator and preserves the first ambiguity origin span.

The type-op behavior I ran into while working on this is split into rust-lang#161423.

Future work: carry the failed outlives predicate or originating binder far enough through this path to name the exact bound that failed, rather than only pointing at its origin.

Rollup merge of #158588 - Dnreikronos:trait_selection/assumptions_binders_diagnostics, r=BoxyUwU

trait_selection: fix assumptions-on-binders diagnostics

fixes #157732

`-Zassumptions-on-binders` was losing the origin of solver region constraints. By the time regionck or borrowck reported them, every constraint received the containing item span, so diagnostics pointed at an entire function or const. Some paths were also still emitting placeholder text (`:3` and `meoow :c`).

This keeps canonical solver responses and `ExternalConstraintsData` span-free, so source locations do not participate in candidate equality or caching. When a response is applied, `EvalCtxt::origin_span` is attached to each atomic solver `RegionConstraint` stored in `InferCtxt`. Late region conversion then uses the span attached to each constraint, including for ambiguity diagnostics.

The affected paths now report `higher-ranked lifetime bound could not be satisfied` at the type use that introduced the failing constraint. UI coverage checks the #157732 call-site diagnostic and the existing regionck alias-outlives case. Unit coverage checks that the spanned evaluator stays in semantic parity with the type-ir evaluator and preserves the first ambiguity origin span.

The type-op behavior I ran into while working on this is split into #161423.

Future work: carry the failed outlives predicate or originating binder far enough through this path to name the exact bound that failed, rather than only pointing at its origin.