Restrict diagnostic context lifetime of InferCtxt to itself instead of TyCtxt

compiler/rustc_trait_selection/src/traits/error_reporting/infer_ctxt_ext.rs

@@ -88,7 +88,7 @@ impl<'tcx> InferCtxt<'tcx> {
         found_args: Vec<ArgKind>,
         is_closure: bool,
         closure_arg_span: Option<Span>,
-    ) -> Diag<'tcx> {
+    ) -> Diag<'_> {
         let kind = if is_closure { "closure" } else { "function" };
 
         let args_str = |arguments: &[ArgKind], other: &[ArgKind]| {

compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs

@@ -3422,7 +3422,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         found_trait_ref: ty::TraitRef<'tcx>,
         expected_trait_ref: ty::TraitRef<'tcx>,
         terr: TypeError<'tcx>,
-    ) -> Diag<'tcx> {
+    ) -> Diag<'a> {
         let self_ty = found_trait_ref.self_ty();
         let (cause, terr) = if let ty::Closure(def_id, _) = self_ty.kind() {
             (
@@ -3553,7 +3553,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                     })
                     .unwrap_or((found_span, None, found));
 
-                self.report_arg_count_mismatch(
+                self.infcx.report_arg_count_mismatch(
                     span,
                     closure_span,
                     expected,