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_hir_def/src/lib.rs b/crates/ra_hir_def/src/lib.rs
index edc59e5a8..af2a717c9 100644
--- a/crates/ra_hir_def/src/lib.rs
+++ b/crates/ra_hir_def/src/lib.rs
@@ -159,7 +159,7 @@ pub struct TypeAliasId(salsa::InternId);
 type TypeAliasLoc = AssocItemLoc<ast::TypeAliasDef>;
 impl_intern!(TypeAliasId, TypeAliasLoc, intern_type_alias, lookup_intern_type_alias);
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Ord, PartialOrd)]
 pub struct ImplId(salsa::InternId);
 type ImplLoc = ItemLoc<ast::ImplDef>;
 impl_intern!(ImplId, ImplLoc, intern_impl, lookup_intern_impl);