Stop pointing to operators if their libcore method source is not available

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -1059,12 +1059,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                     );
                     if self.fn_self_span_reported.insert(fn_span) {
                         err.span_note(
-                            // Check whether the source is accessible
-                            if self.infcx.tcx.sess.source_map().is_span_accessible(self_arg.span) {
-                                self_arg.span
-                            } else {
-                                fn_call_span
-                            },
+                            self_arg.span,
                             "calling this operator moves the left-hand side",
                         );
                     }