These queries appear to have been using `anon` for its side-effect of making
them ineligible for forcing.
According to their comments and also `tests/incremental/issue-61323.rs`, these
queries want to avoid forcing so that if a cycle does occur, the whole cycle
will be on the query stack for the cycle handler to find.
All of the other public items in `rustc_middle::query::plumbing` are
re-exported from `query`, except for these two, for no particular reason that I
can see.
Re-exporting them allows `rustc_middle::query::plumbing` to have its visibility
reduced to pub(crate).
Imports within `rustc_middle` have also been updated to consistently use the
re-exports in `crate::query`.
Unlike `macro_rules!`, macros-2.0 macros have sensible item-like namespacing
and visibility by default, which avoids the need for `#[macro_export]` and
makes it easier to import the macro.
The tradeoff is having to use `#[rustc_macro_transparency = "semiopaque"]` to
still get macro-rules hygiene, because macros-2.0 hygiene is too strict here.
Moving the macro and its expansion into the same physical file resolves a lot
of tension in the current module arrangement.
Code in the macro is now free to use plain imports in the same file, and there
is no longer any question of whether `mod query_impl` should be declared inside
the macro, or surrounding a separate expansion site.
Nicholas Nethercote