Use less `#[macro_use]` in the query system
Macro-rules namespacing and import/export is a bit of a nightmare in general. We can tame it a bit by avoiding `#[macro_use]` as much as possible, and instead putting a `pub(crate) use` after the macro-rules declaration to make the macro importable as a normal item.
I've split this PR into two commits. The first one should hopefully be uncontroversial, while the second commit takes the extra step of declaring `rustc_with_all_queries!` as a macros-2.0 macro, which gives much nicer import/export behaviour, at the expense of having to specify `#[rustc_macro_transparency = "semiopaque"]` to still have access to macro-rules hygiene, because the default macros-2.0 hygiene is too strict here.
There should be no change to compiler behaviour.
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I stumbled into this while investigating some other changes, such as re-exporting `rustc_middle::query::QueryVTable` or moving the big callback macro out of `rustc_middle::query::plumbing`. I think it makes sense to make this change first, to make other module-juggling tasks easier.
r? nnethercote (or compiler)
Matthias Krüger
e167b9b5c4