decl_check: consider outer scopes' allows

Fix #8417. Also makes it less noisy about no_mangle annotated stuff the
user can do nothing about.

Note: this still is broken with bitfield! macros. A repro in an ignore
test is included here. I believe this bug is elsewhere, and I don't
think I can work around it here.

1 files changed, 10 insertions, 0 deletions

diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index e2af0e514..eefc75706 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -435,6 +435,16 @@ impl_from!(
     for AttrDefId
 );
 
+impl From<AssocContainerId> for AttrDefId {
+    fn from(acid: AssocContainerId) -> Self {
+        match acid {
+            AssocContainerId::ModuleId(mid) => AttrDefId::ModuleId(mid),
+            AssocContainerId::ImplId(iid) => AttrDefId::ImplId(iid),
+            AssocContainerId::TraitId(tid) => AttrDefId::TraitId(tid),
+        }
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum VariantId {
     EnumVariantId(EnumVariantId),