Auto merge of #65087 - Centril:rollup-skxq0zr, r=Centril

Rollup of 5 pull requests

Successful merges:

 - #64749 (Fix most remaining Polonius test differences)
 - #64817 (Replace ClosureSubsts with SubstsRef)
 - #64874 (Simplify ExprUseVisitor)
 - #65026 (metadata: Some crate loading cleanup)
 - #65073 (Remove `borrowck_graphviz_postflow` from test)

Failed merges:

r? @ghost

src/librustc/infer/error_reporting/need_type_info.rs

@@ -220,7 +220,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
 
  let ty_msg = match local_visitor.found_ty {
  Some(ty::TyS { kind: ty::Closure(def_id, substs), .. }) => {
- let fn_sig = substs.closure_sig(*def_id, self.tcx);
+ let fn_sig = substs.as_closure().sig(*def_id, self.tcx);
  let args = closure_args(&fn_sig);
  let ret = fn_sig.output().skip_binder().to_string();
  format!(" for the closure `fn({}) -> {}`", args, ret)
@@ -255,7 +255,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
 
  let suffix = match local_visitor.found_ty {
  Some(ty::TyS { kind: ty::Closure(def_id, substs), .. }) => {
- let fn_sig = substs.closure_sig(*def_id, self.tcx);
+ let fn_sig = substs.as_closure().sig(*def_id, self.tcx);
  let ret = fn_sig.output().skip_binder().to_string();
 
  if let Some(ExprKind::Closure(_, decl, body_id, ..)) = local_visitor.found_closure {

src/librustc/infer/mod.rs

@@ -1504,9 +1504,9 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
  pub fn closure_kind(
  &self,
  closure_def_id: DefId,
- closure_substs: ty::ClosureSubsts<'tcx>,
+ closure_substs: SubstsRef<'tcx>,
  ) -> Option<ty::ClosureKind> {
- let closure_kind_ty = closure_substs.closure_kind_ty(closure_def_id, self.tcx);
+ let closure_kind_ty = closure_substs.as_closure().kind_ty(closure_def_id, self.tcx);
  let closure_kind_ty = self.shallow_resolve(closure_kind_ty);
  closure_kind_ty.to_opt_closure_kind()
  }
@@ -1518,9 +1518,9 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
  pub fn closure_sig(
  &self,
  def_id: DefId,
- substs: ty::ClosureSubsts<'tcx>,
+ substs: SubstsRef<'tcx>,
  ) -> ty::PolyFnSig<'tcx> {
- let closure_sig_ty = substs.closure_sig_ty(def_id, self.tcx);
+ let closure_sig_ty = substs.as_closure().sig_ty(def_id, self.tcx);
  let closure_sig_ty = self.shallow_resolve(closure_sig_ty);
  closure_sig_ty.fn_sig(self.tcx)
  }

src/librustc/infer/opaque_types/mod.rs

@@ -722,11 +722,11 @@ where
  ty::Closure(def_id, ref substs) => {
  // Skip lifetime parameters of the enclosing item(s)
 
- for upvar_ty in substs.upvar_tys(def_id, self.tcx) {
+ for upvar_ty in substs.as_closure().upvar_tys(def_id, self.tcx) {
  upvar_ty.visit_with(self);
  }
 
- substs.closure_sig_ty(def_id, self.tcx).visit_with(self);
+ substs.as_closure().sig_ty(def_id, self.tcx).visit_with(self);
  }
 
  ty::Generator(def_id, ref substs, _) => {
@@ -886,7 +886,7 @@ impl TypeFolder<'tcx> for ReverseMapper<'tcx> {
 
  let generics = self.tcx.generics_of(def_id);
  let substs =
- self.tcx.mk_substs(substs.substs.iter().enumerate().map(|(index, &kind)| {
+ self.tcx.mk_substs(substs.iter().enumerate().map(|(index, &kind)| {
  if index < generics.parent_count {
  // Accommodate missing regions in the parent kinds...
  self.fold_kind_mapping_missing_regions_to_empty(kind)
@@ -896,7 +896,7 @@ impl TypeFolder<'tcx> for ReverseMapper<'tcx> {
  }
  }));
 
- self.tcx.mk_closure(def_id, ty::ClosureSubsts { substs })
+ self.tcx.mk_closure(def_id, substs)
  }
 
  ty::Generator(def_id, substs, movability) => {

src/librustc/middle/cstore.rs

@@ -148,9 +148,7 @@ pub enum ExternCrateSource {
  /// such ids
  DefId,
  ),
- // Crate is loaded by `use`.
- Use,
- /// Crate is implicitly loaded by an absolute path.
+ /// Crate is implicitly loaded by a path resolving through extern prelude.
  Path,
 }