Remove separate indexing of early-bound regions

[cjgillot]

Based on #99728.

This PR copies some modifications from #97839 around object lifetime defaults.
These modifications allow to stop counting generic parameters during lifetime resolution, and rely on the indexing given by rustc_typeck::collect.

[rust-highfive]

r? @estebank

(rust-highfive has picked a reviewer for you, use r? to override)

[rustbot]

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

[bors]

☔ The latest upstream changes (presumably #100063) made this pull request unmergeable. Please resolve the merge conflicts.

[estebank]

r? rust-lang/compiler

[nagisa]

r? rust-lang/compiler

I’ll be out on vacation for a while, so I won’t be able to get to this anytime soon.

[nagisa]

(well, highfive should be adjusted somehow to not pass the buck straight back to the original reviewer ^^)

[estebank]

I'm not confident reviewing this PR right now. Let's see if rerolling yields comedy.

r? rust-lang/compiler

[wesleywiser]

I see other places in this PR were updated to handle DefKind::LifetimeParam | DefKind::TyParam | DefKind::ConstParam, should this also check for DefKind::LifetimeParam?

[wesleywiser]

This looks good to me but I'm not an expert in this part of the compiler.

r? rust-lang/types

[compiler-errors]

@bors r+

[bors]

📌 Commit da90ec1 has been approved by compiler-errors

It is now in the queue for this repository.

[nnethercote]

@cjgillot: the perf results here show that this was overall a performance win, but there were some regressions for diesel-1.4.8. Any idea what might be the cause, and how to remedy?

[nnethercote]

Here is the first part of the Cachegrind diff, if that's helpful.

--------------------------------------------------------------------------------
Ir
--------------------------------------------------------------------------------
46,187,526  PROGRAM TOTALS

--------------------------------------------------------------------------------
Ir          file:function
--------------------------------------------------------------------------------
 8,016,144  ???:rustc_resolve::late::lifetimes::object_lifetime_default
 7,919,529  ???:<rustc_metadata::rmeta::encoder::EncodeContext>::encode_def_ids
 7,751,226  ???:rustc_query_system::query::plumbing::try_execute_query::<rustc_query_impl::plumbing::QueryCtxt, rustc_query_system::query::caches::DefaultCache<rustc_span::def_id::DefId, core::option::Option<rustc_middle::middle::resolve_lifetime::ObjectLifetimeDefault>>>
-6,925,800  ???:<rustc_middle::ty::generics::Generics as rustc_serialize::serialize::Encodable<rustc_metadata::rmeta::encoder::EncodeContext>>::encode
 6,027,485  ???:<rustc_hir::hir::WhereBoundPredicate>::is_param_bound
 4,748,382  ???:<alloc::rc::Rc<alloc::vec::Vec<rustc_ast::tokenstream::TokenTree>> as core::ops::drop::Drop>::drop
 2,937,328  ???:<rustc_data_structures::sip128::SipHasher128>::finish128
-2,538,406  ???:<alloc::vec::Vec<rustc_ast::tokenstream::TokenTree> as core::ops::drop::Drop>::drop
-2,508,142  ???:rustc_middle::ty::codec::encode_with_shorthand::<rustc_query_impl::on_disk_cache::CacheEncoder, rustc_middle::ty::Ty, <rustc_query_impl::on_disk_cache::CacheEncoder as rustc_type_ir::codec::TyEncoder>::type_shorthands>
 2,311,692  ???:<hashbrown::raw::RawTable<(rustc_span::def_id::DefId, (core::option::Option<rustc_hir::def::DefKind>, rustc_query_system::dep_graph::graph::DepNodeIndex))>>::reserve_rehash::<hashbrown::map::make_hasher<rustc_span::def_id::DefId, rustc_span::def_id::DefId, (core::option::Option<rustc_hir::def::DefKind>, rustc_query_system::dep_graph::graph::DepNodeIndex), core::hash::BuildHasherDefault<rustc_hash::FxHasher>>::{closure
-2,311,692  ???:<hashbrown::raw::RawTable<(rustc_middle::ty::Ty, usize)>>::reserve_rehash::<hashbrown::map::make_hasher<rustc_middle::ty::Ty, rustc_middle::ty::Ty, usize, core::hash::BuildHasherDefault<rustc_hash::FxHasher>>::{closure
 2,207,430  ???:<rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::try_mark_previous_green::<rustc_query_impl::plumbing::QueryCtxt>
 1,747,207  ???:<std::collections::hash::map::HashMap<rustc_hir::hir_id::ItemLocalId, &rustc_middle::ty::list::List<rustc_middle::ty::subst::GenericArg>, core::hash::BuildHasherDefault<rustc_hash::FxHasher>> as rustc_serialize::serialize::Encodable<rustc_query_impl::on_disk_cache::CacheEncoder>>::encode
 1,621,651  ???:<rustc_span::symbol::Symbol as rustc_serialize::serialize::Encodable<rustc_metadata::rmeta::encoder::EncodeContext>>::encode
 1,335,627  ???:<rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::is_green
 1,320,616  ???:<rustc_middle::dep_graph::dep_node::DepKind as rustc_query_system::dep_graph::DepKind>::read_deps::<<rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::read_index::{closure
 1,277,536  ???:rustc_query_system::query::plumbing::incremental_verify_ich::<rustc_query_impl::plumbing::QueryCtxt, rustc_span::def_id::DefId, core::option::Option<rustc_middle::middle::resolve_lifetime::ObjectLifetimeDefault>>
 1,232,078  ???:<rustc_query_system::dep_graph::graph::DepGraph<rustc_middle::dep_graph::dep_node::DepKind>>::prev_fingerprint_of
 1,225,744  ???:<rustc_middle::hir::map::Map>::get_generics 

[cjgillot]

The main difference I see between diesel, which regresses, and all the other cases is that diesel uses many more trait objects. As this PR changes how object lifetime defaults are computed, having an effect correlated to the presence of trait object is consistent. That said, it does not explain the difference.
The detailed time view would point towards the object_lifetime_default query overhead and metadata generation cost.
I tried #101214 but this does not seem to help.