Auto merge of #120006 - cjgillot:no-hir-owner, r=wesleywiser

Get rid of the hir_owner query.

This query was meant as a firewall between `hir_owner_nodes` which is supposed to change often, and the queries that only depend on the item signature. That firewall was inefficient, leaking the contents of the HIR body through `HirId`s.

`hir_owner` incurs a significant cost, as we need to hash HIR twice in multiple modes. This PR proposes to remove it, and simplify the hashing scheme.

For the future, `def_kind`, `def_span`... are much more efficient for incremental decoupling, and should be preferred.

compiler/rustc_middle/src/query/mod.rs

@@ -174,14 +174,6 @@ rustc_queries! {
         cache_on_disk_if { true }
     }
 
-    /// Gives access to the HIR node for the HIR owner `key`.
-    ///
-    /// This can be conveniently accessed by methods on `tcx.hir()`.
-    /// Avoid calling this query directly.
-    query hir_owner(key: hir::OwnerId) -> Option<crate::hir::Owner<'tcx>> {
-        desc { |tcx| "getting HIR owner of `{}`", tcx.def_path_str(key) }
-    }
-
     /// Gives access to the HIR ID for the given `LocalDefId` owner `key` if any.
     ///
     /// Definitions that were generated with no HIR, would be fed to return `None`.