shallow_resolve stalled vars + conservative include

compiler/rustc_trait_selection/src/solve/fulfill.rs

diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs
index b30850d..e813519 100644
--- a/compiler/rustc_trait_selection/src/solve/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs
@@ -89,8 +89,14 @@ fn clone_pending_potentially_referencing_sub_root(
             .iter()
             .filter(|(_, stalled_on)| {
                 let Some(stalled_on) = stalled_on else { return true };
+                // Conservative here: if any of its stalled vars are not infer var anymore,
+                // some unification happened, so this goal is no longer stalled.
+                // So include it to re-evaluate in the downstream.
                 stalled_on.stalled_vars.iter().filter_map(|arg| arg.as_type()).any(|ty| {
-                    matches!(*ty.kind(), ty::Infer(ty::TyVar(tv)) if infcx.sub_unification_table_root_var(tv) == vid)
+                    match *infcx.shallow_resolve(ty).kind() {
+                        ty::Infer(ty::TyVar(tv)) => infcx.sub_unification_table_root_var(tv) == vid,
+                        _ => true,
+                    }
                 })
             })
             .map(|(o, _)| o.clone())