Auto merge of #103808 - cjgillot:vec-cache, r=TaKO8Ki

Use an IndexVec to cache queries with index-like key

Revival of an old idea. Let's see if it has more effect.

r? `@ghost`

diff --cc compiler/rustc_middle/src/query/mod.rs
Simple merge

diff --cc compiler/rustc_query_impl/src/lib.rs
index 18cb0e0ca0b155695fee806e71ca57909cd9fb99,66d0561c32b0292eda998936db2608eec4674885..e6df6956158bf66ee67a8106e8b86cdbb98b9775
--- 1/compiler/rustc_query_impl/src/lib.rs
--- 2/compiler/rustc_query_impl/src/lib.rs
+++ b/compiler/rustc_query_impl/src/lib.rs
@@@ -32,11 -32,10 +32,10 @@@ use rustc_query_system::query::*
  #[cfg(parallel_compiler)]
  pub use rustc_query_system::query::{deadlock, QueryContext};
  
- mod keys;
- use keys::Key;
+ use rustc_middle::query::Key;
  
  pub use rustc_query_system::query::QueryConfig;
 -pub(crate) use rustc_query_system::query::{QueryDescription, QueryVTable};
 +pub(crate) use rustc_query_system::query::QueryVTable;
  
  mod on_disk_cache;
  pub use on_disk_cache::OnDiskCache;

diff --cc compiler/rustc_query_impl/src/plumbing.rs
Simple merge

diff --cc compiler/rustc_query_system/src/query/mod.rs
Simple merge