…=compiler-errors

Make generic const type mismatches not hide trait impls from the trait solver

pulled out of rust-lang#119895

It does improve diagnostics somewhat, but also causes some extraneous diagnostics in potentially misleading order.

The issue was that a const type mismatch, instead of reporting an error, would silently poison the constant, only for that information to be thrown away and the impl to be treated as "not matching". In rust-lang#119895 this would cause ICEs as well as errors on impls stating that the impl needs to exist for itself to be valid.

…=compiler-errors

Make generic const type mismatches not hide trait impls from the trait solver

pulled out of rust-lang#119895

It does improve diagnostics somewhat, but also causes some extraneous diagnostics in potentially misleading order.

The issue was that a const type mismatch, instead of reporting an error, would silently poison the constant, only for that information to be thrown away and the impl to be treated as "not matching". In rust-lang#119895 this would cause ICEs as well as errors on impls stating that the impl needs to exist for itself to be valid.

…iaskrgr

Rollup of 11 pull requests

Successful merges:

 - rust-lang#117910 (Refactor uses of `objc_msgSend` to no longer have clashing definitions)
 - rust-lang#118639 (Undeprecate lint `unstable_features` and make use of it in the compiler)
 - rust-lang#119801 (Fix deallocation with wrong allocator in (A)Rc::from_box_in)
 - rust-lang#120058 (bootstrap: improvements for compiler builds)
 - rust-lang#120059 (Make generic const type mismatches not hide trait impls from the trait solver)
 - rust-lang#120097 (Report unreachable subpatterns consistently)
 - rust-lang#120137 (Validate AggregateKind types in MIR)
 - rust-lang#120164 (`maybe_lint_impl_trait`: separate `is_downgradable` from `is_object_safe`)
 - rust-lang#120181 (Allow any `const` expression blocks in `thread_local!`)
 - rust-lang#120204 (Builtin macros effectively have implicit #[collapse_debuginfo(yes)])
 - rust-lang#120218 (rustfmt: Check that a token can begin a nonterminal kind before parsing it as a macro arg)

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

…iaskrgr

Rollup of 10 pull requests

Successful merges:

 - rust-lang#117910 (Refactor uses of `objc_msgSend` to no longer have clashing definitions)
 - rust-lang#118639 (Undeprecate lint `unstable_features` and make use of it in the compiler)
 - rust-lang#119801 (Fix deallocation with wrong allocator in (A)Rc::from_box_in)
 - rust-lang#120058 (bootstrap: improvements for compiler builds)
 - rust-lang#120059 (Make generic const type mismatches not hide trait impls from the trait solver)
 - rust-lang#120097 (Report unreachable subpatterns consistently)
 - rust-lang#120137 (Validate AggregateKind types in MIR)
 - rust-lang#120164 (`maybe_lint_impl_trait`: separate `is_downgradable` from `is_object_safe`)
 - rust-lang#120181 (Allow any `const` expression blocks in `thread_local!`)
 - rust-lang#120218 (rustfmt: Check that a token can begin a nonterminal kind before parsing it as a macro arg)

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

Rollup merge of rust-lang#120059 - oli-obk:const_arg_type_mismatch, r=compiler-errors

Make generic const type mismatches not hide trait impls from the trait solver

pulled out of rust-lang#119895

It does improve diagnostics somewhat, but also causes some extraneous diagnostics in potentially misleading order.

The issue was that a const type mismatch, instead of reporting an error, would silently poison the constant, only for that information to be thrown away and the impl to be treated as "not matching". In rust-lang#119895 this would cause ICEs as well as errors on impls stating that the impl needs to exist for itself to be valid.