Replace &mut DiagnosticBuilder, in signatures, with &mut Diagnostic.

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -17,7 +17,7 @@ use rustc_span::{BytePos, Span};
 use crate::diagnostics::BorrowedContentSource;
 use crate::MirBorrowckCtxt;
 use rustc_const_eval::util::collect_writes::FindAssignments;
-use rustc_errors::{Applicability, DiagnosticBuilder};
+use rustc_errors::{Applicability, Diagnostic};
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
 pub(crate) enum AccessKind {
@@ -689,7 +689,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         tcx: TyCtxt<'_>,
         id: &hir::def_id::DefId,
         the_place_err: PlaceRef<'tcx>,
-        err: &mut DiagnosticBuilder<'_>,
+        err: &mut Diagnostic,
     ) {
         let closure_local_def_id = id.expect_local();
         let tables = tcx.typeck(closure_local_def_id);
@@ -754,7 +754,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
     // Attempt to search similar mutable associated items for suggestion.
     // In the future, attempt in all path but initially for RHS of for_loop
-    fn suggest_similar_mut_method_for_for_loop(&self, err: &mut DiagnosticBuilder<'_>) {
+    fn suggest_similar_mut_method_for_for_loop(&self, err: &mut Diagnostic) {
         use hir::{
             BodyId, Expr,
             ExprKind::{Block, Call, DropTemps, Match, MethodCall},
@@ -843,7 +843,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     }
 
     /// Targeted error when encountering an `FnMut` closure where an `Fn` closure was expected.
-    fn expected_fn_found_fn_mut_call(&self, err: &mut DiagnosticBuilder<'_>, sp: Span, act: &str) {
+    fn expected_fn_found_fn_mut_call(&self, err: &mut Diagnostic, sp: Span, act: &str) {
         err.span_label(sp, format!("cannot {}", act));
 
         let hir = self.infcx.tcx.hir();