[benchmarks] Suppress some lints

Change-Id: I7be54b9f8fa2d3534663b6033e74f5f262ad08f9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/449682
Reviewed-by: Mayank Patke <fishythefish@google.com>
Commit-Queue: Stephen Adams <sra@google.com>

benchmarks/BigIntParsePrint/dart/native_version_javascript.dart

@@ -5,6 +5,7 @@
 @JS()
 library native_version_javascript;
 
+// ignore: deprecated_member_use
 import 'package:js/js.dart';
 import 'native_version.dart';
 

benchmarks/InvarianceQueue/dart/InvarianceQueue.dart

@@ -36,6 +36,8 @@
 // mixins because some implementations expand mixins, which could result in the
 // expanded code having non-parametric types, e.g. `Queue<int>`.
 
+// ignore_for_file: prefer_final_locals
+
 import 'dart:typed_data';
 import 'package:benchmark_harness/benchmark_harness.dart';
 

benchmarks/UiMatrix/dart/UiMatrixHarness.dart

@@ -4,6 +4,8 @@
 
 /// Various math benchmarks from https://github.com/yjbanov/uimatrix
 
+// ignore_for_file: deprecated_member_use
+
 import 'dart:math' as math;
 
 import 'package:benchmark_harness/benchmark_harness.dart';