…=compiler-errors

Clean up AstConv

Split off from rust-lang#120926 to make it only contain the renaming & (doc) comment updates.
Any changes other than that which have accumulated over time are now part of this PR.
Let's be disciplined ;) Inspired by rust-lang#120926 (comment).

---

* Remove `hir_trait_to_predicates`
  * Unused since rust-lang#113671
* Inline `create_args_for_ast_trait_ref`
  * Only had a single call site
  * Having it as a separate method didn't gain us anything
* Use an if-let guard somewhere to avoid unwrapping
* Avoid explicit trait object lifetimes
  * More legible, stylistic-only (the updated code is 100% semantically identical)
  * Use explicitly elided lifetimes in impl headers, they get elaborated to distinct lifetimes
  * Make use of [object lifetime defaulting](https://doc.rust-lang.org/reference/lifetime-elision.html#default-trait-object-lifetimes) for a trait object type inside of a reference type somewhere
* Use preexisting dedicated method `ItemCtxt::to_ty` over `<dyn AstConv<'_>>::ast_ty_to_ty`
* Use preexisting dedicated method `AstConv::astconv` over explicit coercions
* Simplify the function signature of `create_args_for_ast_path` and of `check_generic_arg_count`
  * In both cases redundant information was passed rendering the call sites verbose and confusing
  * No perf impact (tested in [rust-lang#120926](rust-lang#120926))
* Move diagnostic method `report_ambiguous_associated_type` from `astconv` to `astconv::errors`
  * The submodule `errors` exists specifically for that purpose
  * Use it to keep the main module clean & short

…iaskrgr

Rollup of 5 pull requests

Successful merges:

 - rust-lang#121885 (Move generic `NonZero` `rustc_layout_scalar_valid_range_start` attribute to inner type.)
 - rust-lang#122471 (preserve span when evaluating mir::ConstOperand)
 - rust-lang#122515 (Pass the correct DefId when suggesting writing the aliased Self type out)
 - rust-lang#122523 (Ensure RPITITs are created before def-id freezing)
 - rust-lang#122527 (Clean up AstConv)

r? `@ghost`
`@rustbot` modify labels: rollup

…iaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#121207 (Add `-Z external-clangrt`)
 - rust-lang#122174 (diagnostics: suggest `Clone` bounds when noop `clone()`)
 - rust-lang#122471 (preserve span when evaluating mir::ConstOperand)
 - rust-lang#122515 (Pass the correct DefId when suggesting writing the aliased Self type out)
 - rust-lang#122523 (Ensure RPITITs are created before def-id freezing)
 - rust-lang#122526 (Docs for `thir::ExprKind::Use` and `thir::ExprKind::Let`)
 - rust-lang#122527 (Clean up AstConv)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of rust-lang#122527 - fmease:clean-up-hir-ty-lowering, r=compiler-errors

Clean up AstConv

Split off from rust-lang#120926 to make it only contain the renaming & (doc) comment updates.
Any changes other than that which have accumulated over time are now part of this PR.
Let's be disciplined ;) Inspired by rust-lang#120926 (comment).

---

* Remove `hir_trait_to_predicates`
  * Unused since rust-lang#113671
* Inline `create_args_for_ast_trait_ref`
  * Only had a single call site
  * Having it as a separate method didn't gain us anything
* Use an if-let guard somewhere to avoid unwrapping
* Avoid explicit trait object lifetimes
  * More legible, stylistic-only (the updated code is 100% semantically identical)
  * Use explicitly elided lifetimes in impl headers, they get elaborated to distinct lifetimes
  * Make use of [object lifetime defaulting](https://doc.rust-lang.org/reference/lifetime-elision.html#default-trait-object-lifetimes) for a trait object type inside of a reference type somewhere
* Use preexisting dedicated method `ItemCtxt::to_ty` over `<dyn AstConv<'_>>::ast_ty_to_ty`
* Use preexisting dedicated method `AstConv::astconv` over explicit coercions
* Simplify the function signature of `create_args_for_ast_path` and of `check_generic_arg_count`
  * In both cases redundant information was passed rendering the call sites verbose and confusing
  * No perf impact (tested in [rust-lang#120926](rust-lang#120926))
* Move diagnostic method `report_ambiguous_associated_type` from `astconv` to `astconv::errors`
  * The submodule `errors` exists specifically for that purpose
  * Use it to keep the main module clean & short

…piler-errors

Remove obsolete parameter `speculative` from `instantiate_poly_trait_ref`

In rust-lang#122527 I totally missed that `speculative` has become obsolete with the removal of `hir_trait_to_predicates` / due to rust-lang#113671.

Fixes rust-lang#114635.

r? `@compiler-errors`

Rollup merge of rust-lang#122577 - fmease:speculative-say-what, r=compiler-errors

Remove obsolete parameter `speculative` from `instantiate_poly_trait_ref`

In rust-lang#122527 I totally missed that `speculative` has become obsolete with the removal of `hir_trait_to_predicates` / due to rust-lang#113671.

Fixes rust-lang#114635.

r? `@compiler-errors`