Structurally resolve in probe_adt

compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs

@@ -307,7 +307,11 @@ impl<'tcx> HirTyLowerer<'tcx> for FnCtxt<'_, 'tcx> {
             ty::Alias(ty::Projection | ty::Inherent | ty::Weak, _)
                 if !ty.has_escaping_bound_vars() =>
             {
-                self.normalize(span, ty).ty_adt_def()
+                if self.next_trait_solver() {
+                    self.try_structurally_resolve_type(span, ty).ty_adt_def()
+                } else {
+                    self.normalize(span, ty).ty_adt_def()
+                }
             }
             _ => None,
         }

tests/ui/traits/next-solver/typeck/structurally-resolve-in-probe_adt.rs

@@ -0,0 +1,15 @@
+//@ check-pass
+//@ compile-flags: -Znext-solver
+
+trait Mirror {
+    type Assoc;
+}
+impl<T> Mirror for T {
+    type Assoc = T;
+}
+
+type Foo<T> = <Option<T> as Mirror>::Assoc;
+
+fn main() {
+    let x = Foo::<i32>::None;
+}