Enable drop_tracking_mir by default.

Author: cjgillot

compiler/rustc_hir_analysis/src/check/check.rs

@@ -1579,13 +1579,7 @@ fn opaque_type_cycle_error(
                         label_match(capture.place.ty(), capture.get_path_span(tcx));
                     }
                     // Label any generator locals that capture the opaque
-                    for interior_ty in
-                        typeck_results.generator_interior_types.as_ref().skip_binder()
-                    {
-                        label_match(interior_ty.ty, interior_ty.span);
-                    }
-                    if tcx.sess.opts.unstable_opts.drop_tracking_mir
-                        && let DefKind::Generator = tcx.def_kind(closure_def_id)
+                    if let DefKind::Generator = tcx.def_kind(closure_def_id)
                         && let Some(generator_layout) = tcx.mir_generator_witnesses(closure_def_id)
                     {
                         for interior_ty in &generator_layout.field_tys {
@@ -1603,7 +1597,6 @@ fn opaque_type_cycle_error(
 }
 
 pub(super) fn check_generator_obligations(tcx: TyCtxt<'_>, def_id: LocalDefId) {
-    debug_assert!(tcx.sess.opts.unstable_opts.drop_tracking_mir);
     debug_assert!(matches!(tcx.def_kind(def_id), DefKind::Generator));
 
     let typeck = tcx.typeck(def_id);

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -510,25 +510,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     }
 
     pub(in super::super) fn resolve_generator_interiors(&self, def_id: DefId) {
-        if self.tcx.sess.opts.unstable_opts.drop_tracking_mir {
-            self.save_generator_interior_predicates(def_id);
-            return;
-        }
-
-        self.select_obligations_where_possible(|_| {});
-
-        let mut generators = self.deferred_generator_interiors.borrow_mut();
-        for (generator_def_id, body_id, interior, kind) in generators.drain(..) {
-            crate::generator_interior::resolve_interior(
-                self,
-                def_id,
-                generator_def_id,
-                body_id,
-                interior,
-                kind,
-            );
-            self.select_obligations_where_possible(|_| {});
-        }
+        self.save_generator_interior_predicates(def_id);
     }
 
     /// Unify the inference variables corresponding to generator witnesses, and save all the