Merge #4947

4947: Replace `impls_in_trait` query with smarter use of `CrateImplDefs` r=matklad a=jonas-schievink

`impls_in_trait` was allocating a whopping ~400 MB of RAM when running analysis-stats on r-a itself.

Remove it, instead adding a query that computes a summary `CrateImplDefs` map for all transitive dependencies. This can probably still be made more efficient, but this already reduces the peak memory usage by 25% without much performance impact on analysis-stats.

**Before**:

```
Total: 34.962107188s, 2083mb allocated 2141mb resident
   422mb ImplsForTraitQuery (deps)
   250mb CrateDefMapQueryQuery
   147mb MacroArgQuery
   140mb TraitSolveQuery (deps)
    68mb InferQueryQuery (deps)
    62mb ImplDatumQuery (deps)
```

**After**:

```
Total: 35.261100358s, 1520mb allocated 1569mb resident
   250mb CrateDefMapQueryQuery
   147mb MacroArgQuery
   144mb TraitSolveQuery (deps)
    68mb InferQueryQuery (deps)
    61mb ImplDatumQuery (deps)
    45mb BodyQuery
    45mb ImplDatumQuery
```

Co-authored-by: Jonas Schievink <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/crates/ra_ide_db/src/change.rs b/crates/ra_ide_db/src/change.rs
index 78ee6a515..98993d571 100644
--- a/crates/ra_ide_db/src/change.rs
+++ b/crates/ra_ide_db/src/change.rs
@@ -283,7 +283,7 @@ impl RootDatabase {
             hir::db::GenericPredicatesQuery
             hir::db::GenericDefaultsQuery
             hir::db::ImplsInCrateQuery
-            hir::db::ImplsForTraitQuery
+            hir::db::ImplsFromDepsQuery
             hir::db::InternTypeCtorQuery
             hir::db::InternTypeParamIdQuery
             hir::db::InternChalkImplQuery