Fortify find_entry.

Author: cjgillot

compiler/rustc_middle/src/hir/map/mod.rs

@@ -267,19 +267,17 @@ impl<'hir> Map<'hir> {
 
     fn find_entry(&self, id: HirId) -> Option<Entry<'hir>> {
         if id.local_id == ItemLocalId::from_u32(0) {
-            let owner = self.tcx.hir_owner(id.owner);
-            owner.map(|owner| Entry { parent: owner.parent, node: owner.node })
+            let owner = self.tcx.hir_owner(id.owner)?;
+            Some(Entry { parent: owner.parent, node: owner.node })
         } else {
-            let owner = self.tcx.hir_owner_nodes(id.owner);
-            owner.and_then(|owner| {
-                let node = owner.nodes[id.local_id].as_ref();
-                // FIXME(eddyb) use a single generic type insted of having both
-                // `Entry` and `ParentedNode`, which are effectively the same.
-                // Alternatively, rewrite code using `Entry` to use `ParentedNode`.
-                node.map(|node| Entry {
-                    parent: HirId { owner: id.owner, local_id: node.parent },
-                    node: node.node,
-                })
+            let owner = self.tcx.hir_owner_nodes(id.owner)?;
+            let node = owner.nodes.get(id.local_id)?.as_ref()?;
+            // FIXME(eddyb) use a single generic type insted of having both
+            // `Entry` and `ParentedNode`, which are effectively the same.
+            // Alternatively, rewrite code using `Entry` to use `ParentedNode`.
+            Some(Entry {
+                parent: HirId { owner: id.owner, local_id: node.parent },
+                node: node.node,
             })
         }
     }