Auto merge of #92805 - BoxyUwU:revert-lazy-anon-const-substs, r=lcnr

partially revertish `lazily "compute" anon const default substs`

reverts #87280 except for some of the changes around `ty::Unevaluated` having a visitor and a generic for promoted
why revert: <#92805 (comment)>

r? `@lcnr`

Author: bors

compiler/rustc_borrowck/src/type_check/liveness/trace.rs

@@ -171,7 +171,7 @@ impl<'me, 'typeck, 'flow, 'tcx> LivenessResults<'me, 'typeck, 'flow, 'tcx> {
         for (local, location) in drop_used {
             if !live_locals.contains(&local) {
                 let local_ty = self.cx.body.local_decls[local].ty;
-                if local_ty.has_free_regions(self.cx.typeck.tcx()) {
+                if local_ty.has_free_regions() {
                     self.cx.add_drop_live_facts_for(local, local_ty, &[location], &locations);
                 }
             }

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -426,7 +426,7 @@ impl<'a, 'b, 'tcx> Visitor<'tcx> for TypeVerifier<'a, 'b, 'tcx> {
                         self.cx.param_env.and(type_op::ascribe_user_type::AscribeUserType::new(
                             constant.literal.ty(),
                             uv.def.did,
-                            UserSubsts { substs: uv.substs(self.tcx()), user_self_ty: None },
+                            UserSubsts { substs: uv.substs, user_self_ty: None },
                         )),
                     ) {
                         span_mirbug!(
@@ -1970,7 +1970,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                         let predicates = self.prove_closure_bounds(
                             tcx,
                             def_id.expect_local(),
-                            uv.substs(tcx),
+                            uv.substs,
                             location,
                         );
                         self.normalize_and_prove_instantiated_predicates(