`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.
Adjust `#[macro_export]`/doctest help suggestion for non_local_defs lint
This PR adjust the help suggestion of the `non_local_definitions` lint when encountering a `#[macro_export]` at top-level doctest.
So instead of a non-sentential help suggestion to move the `macro_rules!` up above the `rustdoc`-generated function. We now suggest users to declare their own function.
Fixes *(partially, needs backport)* #124534
Fix trait solver overflow with `non_local_definitions` lint
This PR fixes the trait solver overflow with the `non_local_definitions` lint reported in https://github.com/rust-lang/rust/issues/123573 using the suggestion from `@lcnr:` https://github.com/rust-lang/rust/issues/123573#issuecomment-2041348320 to use the next trait solver.
~~I have not (yet) tried to create a minimized repro~~ ``@compiler-errors`` did the minimization (thanks you) but I have manually tested on the `starlark-rust` project that it fixes the issue.
Fixes#123573
r? `@lcnr`
