Revert "Rollup merge of #101496 - spastorino:lower_lifetime_binder_api_changes, r=oli-obk"

This reverts commit 953a6b3da7016d41816951ad0930922f558c16d0, reversing
changes made to b5ffbd32d4838a460a73ce9aa106a4e1856e52c0.

2 files changed, 51 insertions, 66 deletions

diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index cd03e3fb457..2993f1939ea 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -855,22 +855,21 @@ impl<'hir> LoweringContext<'_, 'hir> {
             (body_id, generator_option)
         });
 
-        self.lower_lifetime_binder(closure_id, generic_params, |lctx, bound_generic_params| {
-            // Lower outside new scope to preserve `is_in_loop_condition`.
-            let fn_decl = lctx.lower_fn_decl(decl, None, fn_decl_span, FnDeclKind::Closure, None);
-
-            let c = lctx.arena.alloc(hir::Closure {
-                binder: binder_clause,
-                capture_clause,
-                bound_generic_params,
-                fn_decl,
-                body: body_id,
-                fn_decl_span: lctx.lower_span(fn_decl_span),
-                movability: generator_option,
-            });
+        let bound_generic_params = self.lower_lifetime_binder(closure_id, generic_params);
+        // Lower outside new scope to preserve `is_in_loop_condition`.
+        let fn_decl = self.lower_fn_decl(decl, None, fn_decl_span, FnDeclKind::Closure, None);
+
+        let c = self.arena.alloc(hir::Closure {
+            binder: binder_clause,
+            capture_clause,
+            bound_generic_params,
+            fn_decl,
+            body: body_id,
+            fn_decl_span: self.lower_span(fn_decl_span),
+            movability: generator_option,
+        });
 
-            hir::ExprKind::Closure(c)
-        })
+        hir::ExprKind::Closure(c)
     }
 
     fn generator_movability_for_fn(
@@ -957,24 +956,23 @@ impl<'hir> LoweringContext<'_, 'hir> {
             body_id
         });
 
-        self.lower_lifetime_binder(closure_id, generic_params, |lctx, bound_generic_params| {
-            // We need to lower the declaration outside the new scope, because we
-            // have to conserve the state of being inside a loop condition for the
-            // closure argument types.
-            let fn_decl =
-                lctx.lower_fn_decl(&outer_decl, None, fn_decl_span, FnDeclKind::Closure, None);
-
-            let c = lctx.arena.alloc(hir::Closure {
-                binder: binder_clause,
-                capture_clause,
-                bound_generic_params,
-                fn_decl,
-                body,
-                fn_decl_span: lctx.lower_span(fn_decl_span),
-                movability: None,
-            });
-            hir::ExprKind::Closure(c)
-        })
+        let bound_generic_params = self.lower_lifetime_binder(closure_id, generic_params);
+        // We need to lower the declaration outside the new scope, because we
+        // have to conserve the state of being inside a loop condition for the
+        // closure argument types.
+        let fn_decl =
+            self.lower_fn_decl(&outer_decl, None, fn_decl_span, FnDeclKind::Closure, None);
+
+        let c = self.arena.alloc(hir::Closure {
+            binder: binder_clause,
+            capture_clause,
+            bound_generic_params,
+            fn_decl,
+            body,
+            fn_decl_span: self.lower_span(fn_decl_span),
+            movability: None,
+        });
+        hir::ExprKind::Closure(c)
     }
 
     /// Destructure the LHS of complex assignments.
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 409ee55268c..c96e419566d 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -839,31 +839,23 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     /// name resolver owing to lifetime elision; this also populates the resolver's node-id->def-id
     /// map, so that later calls to `opt_node_id_to_def_id` that refer to these extra lifetime
     /// parameters will be successful.
-    #[instrument(level = "debug", skip(self, in_binder))]
+    #[instrument(level = "debug", skip(self))]
     #[inline]
-    fn lower_lifetime_binder<R>(
+    fn lower_lifetime_binder(
         &mut self,
         binder: NodeId,
         generic_params: &[GenericParam],
-        in_binder: impl FnOnce(&mut Self, &'hir [hir::GenericParam<'hir>]) -> R,
-    ) -> R {
+    ) -> &'hir [hir::GenericParam<'hir>] {
+        let mut generic_params: Vec<_> = self.lower_generic_params_mut(generic_params).collect();
         let extra_lifetimes = self.resolver.take_extra_lifetime_params(binder);
         debug!(?extra_lifetimes);
-        let extra_lifetimes: Vec<_> = extra_lifetimes
-            .into_iter()
-            .filter_map(|(ident, node_id, res)| {
-                self.lifetime_res_to_generic_param(ident, node_id, res)
-            })
-            .collect();
-
-        let generic_params: Vec<_> = self
-            .lower_generic_params_mut(generic_params)
-            .chain(extra_lifetimes.into_iter())
-            .collect();
+        generic_params.extend(extra_lifetimes.into_iter().filter_map(|(ident, node_id, res)| {
+            self.lifetime_res_to_generic_param(ident, node_id, res)
+        }));
         let generic_params = self.arena.alloc_from_iter(generic_params);
         debug!(?generic_params);
 
-        in_binder(self, generic_params)
+        generic_params
     }
 
     fn with_dyn_type_scope<T>(&mut self, in_scope: bool, f: impl FnOnce(&mut Self) -> T) -> T {
@@ -1268,15 +1260,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 hir::TyKind::Rptr(lifetime, self.lower_mt(mt, itctx))
             }
             TyKind::BareFn(ref f) => {
-                self.lower_lifetime_binder(t.id, &f.generic_params, |lctx, generic_params| {
-                    hir::TyKind::BareFn(lctx.arena.alloc(hir::BareFnTy {
-                        generic_params,
-                        unsafety: lctx.lower_unsafety(f.unsafety),
-                        abi: lctx.lower_extern(f.ext),
-                        decl: lctx.lower_fn_decl(&f.decl, None, t.span, FnDeclKind::Pointer, None),
-                        param_names: lctx.lower_fn_params_to_names(&f.decl),
-                    }))
-                })
+                let generic_params = self.lower_lifetime_binder(t.id, &f.generic_params);
+                hir::TyKind::BareFn(self.arena.alloc(hir::BareFnTy {
+                    generic_params,
+                    unsafety: self.lower_unsafety(f.unsafety),
+                    abi: self.lower_extern(f.ext),
+                    decl: self.lower_fn_decl(&f.decl, None, t.span, FnDeclKind::Pointer, None),
+                    param_names: self.lower_fn_params_to_names(&f.decl),
+                }))
             }
             TyKind::Never => hir::TyKind::Never,
             TyKind::Tup(ref tys) => hir::TyKind::Tup(
@@ -2246,14 +2237,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         p: &PolyTraitRef,
         itctx: &mut ImplTraitContext,
     ) -> hir::PolyTraitRef<'hir> {
-        self.lower_lifetime_binder(
-            p.trait_ref.ref_id,
-            &p.bound_generic_params,
-            |lctx, bound_generic_params| {
-                let trait_ref = lctx.lower_trait_ref(&p.trait_ref, itctx);
-                hir::PolyTraitRef { bound_generic_params, trait_ref, span: lctx.lower_span(p.span) }
-            },
-        )
+        let bound_generic_params =
+            self.lower_lifetime_binder(p.trait_ref.ref_id, &p.bound_generic_params);
+        let trait_ref = self.lower_trait_ref(&p.trait_ref, itctx);
+        hir::PolyTraitRef { bound_generic_params, trait_ref, span: self.lower_span(p.span) }
     }
 
     fn lower_mt(&mut self, mt: &MutTy, itctx: &mut ImplTraitContext) -> hir::MutTy<'hir> {