Auto merge of rust-lang#89158 - the8472:rollup-3e4ijth, r=the8472

Rollup of 12 pull requests

Successful merges:

 - rust-lang#88795 (Print a note if a character literal contains a variation selector)
 - rust-lang#89015 (core::ascii::escape_default: reduce struct size)
 - rust-lang#89078 (Cleanup: Remove needless reference in ParentHirIterator)
 - rust-lang#89086 (Stabilize `Iterator::map_while`)
 - rust-lang#89096 ([bootstrap] Improve the error message when `ninja` is not found to link to installation instructions)
 - rust-lang#89113 (dont `.ensure()` the `thir_abstract_const` query call in `mir_build`)
 - rust-lang#89114 (Fixes a technicality regarding the size of C's `char` type)
 - rust-lang#89115 (:arrow_up: rust-analyzer)
 - rust-lang#89126 (Fix ICE when `indirect_structural_match` is allowed)
 - rust-lang#89141 (Impl `Error` for `FromSecsError` without foreign type)
 - rust-lang#89142 (Fix match for placeholder region)
 - rust-lang#89147 (add case for checking const refs in check_const_value_eq)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

clippy_utils/src/higher.rs

@@ -105,8 +105,7 @@ impl<'hir> IfLet<'hir> {
             if_else,
         ) = expr.kind
         {
-            let hir = cx.tcx.hir();
-            let mut iter = hir.parent_iter(expr.hir_id);
+            let mut iter = cx.tcx.hir().parent_iter(expr.hir_id);
             if let Some((_, Node::Block(Block { stmts: [], .. }))) = iter.next() {
                 if let Some((
                     _,

clippy_utils/src/lib.rs

@@ -833,12 +833,11 @@ pub fn capture_local_usage(cx: &LateContext<'tcx>, e: &Expr<'_>) -> CaptureKind
         ExprKind::Path(QPath::Resolved(None, Path { res: Res::Local(_), .. }))
     ));
 
-    let map = cx.tcx.hir();
     let mut child_id = e.hir_id;
     let mut capture = CaptureKind::Value;
     let mut capture_expr_ty = e;
 
-    for (parent_id, parent) in map.parent_iter(e.hir_id) {
+    for (parent_id, parent) in cx.tcx.hir().parent_iter(e.hir_id) {
         if let [Adjustment {
             kind: Adjust::Deref(_) | Adjust::Borrow(AutoBorrow::Ref(..)),
             target,
@@ -1224,8 +1223,7 @@ pub fn get_enclosing_block<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId) -> Optio
 
 /// Gets the loop or closure enclosing the given expression, if any.
 pub fn get_enclosing_loop_or_closure(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
-    let map = tcx.hir();
-    for (_, node) in map.parent_iter(expr.hir_id) {
+    for (_, node) in tcx.hir().parent_iter(expr.hir_id) {
         match node {
             Node::Expr(
                 e
@@ -1244,8 +1242,7 @@ pub fn get_enclosing_loop_or_closure(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Opti
 
 /// Gets the parent node if it's an impl block.
 pub fn get_parent_as_impl(tcx: TyCtxt<'_>, id: HirId) -> Option<&Impl<'_>> {
-    let map = tcx.hir();
-    match map.parent_iter(id).next() {
+    match tcx.hir().parent_iter(id).next() {
         Some((
             _,
             Node::Item(Item {
@@ -1259,8 +1256,7 @@ pub fn get_parent_as_impl(tcx: TyCtxt<'_>, id: HirId) -> Option<&Impl<'_>> {
 
 /// Checks if the given expression is the else clause of either an `if` or `if let` expression.
 pub fn is_else_clause(tcx: TyCtxt<'_>, expr: &Expr<'_>) -> bool {
-    let map = tcx.hir();
-    let mut iter = map.parent_iter(expr.hir_id);
+    let mut iter = tcx.hir().parent_iter(expr.hir_id);
     match iter.next() {
         Some((
             _,
@@ -1794,9 +1790,8 @@ pub fn is_expr_identity_function(cx: &LateContext<'_>, expr: &Expr<'_>) -> bool
 
 /// Gets the node where an expression is either used, or it's type is unified with another branch.
 pub fn get_expr_use_or_unification_node(tcx: TyCtxt<'tcx>, expr: &Expr<'_>) -> Option<Node<'tcx>> {
-    let map = tcx.hir();
     let mut child_id = expr.hir_id;
-    let mut iter = map.parent_iter(child_id);
+    let mut iter = tcx.hir().parent_iter(child_id);
     loop {
         match iter.next() {
             None => break None,