Unrolled build for rust-lang#120872

Rollup merge of rust-lang#120872 - petrochenkov:opthirpar, r=cjgillot

hir: Refactor getters for HIR parents

See individual commits.

I ended up removing on of the FIXMEs from rust-lang#120206 instead of addressing it.

Author: rust-timer

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -403,8 +403,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     }
                 }
                 let typeck = self.infcx.tcx.typeck(self.mir_def_id());
-                let hir_id = hir.parent_id(expr.hir_id);
-                let parent = self.infcx.tcx.hir_node(hir_id);
+                let parent = self.infcx.tcx.parent_hir_node(expr.hir_id);
                 let (def_id, args, offset) = if let hir::Node::Expr(parent_expr) = parent
                     && let hir::ExprKind::MethodCall(_, _, args, _) = parent_expr.kind
                     && let Some(def_id) = typeck.type_dependent_def_id(parent_expr.hir_id)
@@ -1660,8 +1659,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
 
         // Check that the parent of the closure is a method call,
         // with receiver matching with local's type (modulo refs)
-        let parent = hir.parent_id(closure_expr.hir_id);
-        if let hir::Node::Expr(parent) = tcx.hir_node(parent) {
+        if let hir::Node::Expr(parent) = tcx.parent_hir_node(closure_expr.hir_id) {
             if let hir::ExprKind::MethodCall(_, recv, ..) = parent.kind {
                 let recv_ty = typeck_results.expr_ty(recv);
 

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -944,7 +944,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         let hir = self.infcx.tcx.hir();
         let closure_id = self.mir_hir_id();
         let closure_span = self.infcx.tcx.def_span(self.mir_def_id());
-        let fn_call_id = hir.parent_id(closure_id);
+        let fn_call_id = self.infcx.tcx.parent_hir_id(closure_id);
         let node = self.infcx.tcx.hir_node(fn_call_id);
         let def_id = hir.enclosing_body_owner(fn_call_id);
         let mut look_at_return = true;
@@ -1034,7 +1034,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         if let InstanceDef::Item(def_id) = source.instance
             && let Some(Node::Expr(hir::Expr { hir_id, kind, .. })) = hir.get_if_local(def_id)
             && let ExprKind::Closure(hir::Closure { kind: hir::ClosureKind::Closure, .. }) = kind
-            && let Some(Node::Expr(expr)) = hir.find_parent(*hir_id)
+            && let Node::Expr(expr) = self.infcx.tcx.parent_hir_node(*hir_id)
         {
             let mut cur_expr = expr;
             while let ExprKind::MethodCall(path_segment, recv, _, _) = cur_expr.kind {