Store ForeignItem in a side table.

compiler/rustc_passes/src/dead.rs

@@ -447,6 +447,8 @@ impl<'v, 'k, 'tcx> ItemLikeVisitor<'v> for LifeSeeder<'k, 'tcx> {
     fn visit_impl_item(&mut self, _item: &hir::ImplItem<'_>) {
         // ignore: we are handling this in `visit_item` above
     }
+
+    fn visit_foreign_item(&mut self, _item: &'v hir::ForeignItem<'v>) {}
 }
 
 fn create_and_seed_worklist<'tcx>(

compiler/rustc_passes/src/diagnostic_items.rs

@@ -37,6 +37,8 @@ impl<'v, 'tcx> ItemLikeVisitor<'v> for DiagnosticItemCollector<'tcx> {
     fn visit_impl_item(&mut self, impl_item: &hir::ImplItem<'_>) {
         self.observe_item(&impl_item.attrs, impl_item.hir_id);
     }
+
+    fn visit_foreign_item(&mut self, _foreign_item: &hir::ForeignItem<'_>) {}
 }
 
 impl<'tcx> DiagnosticItemCollector<'tcx> {

compiler/rustc_passes/src/entry.rs

@@ -2,7 +2,7 @@ use rustc_ast::entry::EntryPointType;
 use rustc_errors::struct_span_err;
 use rustc_hir::def_id::{CrateNum, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
 use rustc_hir::itemlikevisit::ItemLikeVisitor;
-use rustc_hir::{HirId, ImplItem, Item, ItemKind, TraitItem};
+use rustc_hir::{ForeignItem, HirId, ImplItem, Item, ItemKind, TraitItem};
 use rustc_middle::hir::map::Map;
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::TyCtxt;
@@ -45,6 +45,8 @@ impl<'a, 'tcx> ItemLikeVisitor<'tcx> for EntryContext<'a, 'tcx> {
     fn visit_impl_item(&mut self, _impl_item: &'tcx ImplItem<'tcx>) {
         // Entry fn is never a trait item.
     }
+
+    fn visit_foreign_item(&mut self, _: &'tcx ForeignItem<'tcx>) {}
 }
 
 fn entry_fn(tcx: TyCtxt<'_>, cnum: CrateNum) -> Option<(LocalDefId, EntryFnType)> {

compiler/rustc_passes/src/hir_id_validator.rs

@@ -68,6 +68,11 @@ impl<'a, 'hir> ItemLikeVisitor<'hir> for OuterVisitor<'a, 'hir> {
         let mut inner_visitor = self.new_inner_visitor(self.hir_map);
         inner_visitor.check(i.hir_id, |this| intravisit::walk_impl_item(this, i));
     }
+
+    fn visit_foreign_item(&mut self, i: &'hir hir::ForeignItem<'hir>) {
+        let mut inner_visitor = self.new_inner_visitor(self.hir_map);
+        inner_visitor.check(i.hir_id, |this| intravisit::walk_foreign_item(this, i));
+    }
 }
 
 impl<'a, 'hir> HirIdValidator<'a, 'hir> {

compiler/rustc_passes/src/lang_items.rs

@@ -54,6 +54,8 @@ impl ItemLikeVisitor<'v> for LanguageItemCollector<'tcx> {
             impl_item.attrs,
         )
     }
+
+    fn visit_foreign_item(&mut self, _: &hir::ForeignItem<'_>) {}
 }
 
 impl LanguageItemCollector<'tcx> {

compiler/rustc_passes/src/layout_test.rs

@@ -40,6 +40,7 @@ impl ItemLikeVisitor<'tcx> for LayoutTest<'tcx> {
 
     fn visit_trait_item(&mut self, _: &'tcx hir::TraitItem<'tcx>) {}
     fn visit_impl_item(&mut self, _: &'tcx hir::ImplItem<'tcx>) {}
+    fn visit_foreign_item(&mut self, _: &'tcx hir::ForeignItem<'tcx>) {}
 }
 
 impl LayoutTest<'tcx> {

compiler/rustc_passes/src/reachable.rs

@@ -378,6 +378,8 @@ impl<'a, 'tcx> ItemLikeVisitor<'tcx> for CollectPrivateImplItemsVisitor<'a, 'tcx
     fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem<'_>) {
         // processed in visit_item above
     }
+
+    fn visit_foreign_item(&mut self, _foreign_item: &hir::ForeignItem<'_>) {}
 }
 
 fn reachable_set<'tcx>(tcx: TyCtxt<'tcx>, crate_num: CrateNum) -> FxHashSet<LocalDefId> {