linter: sort imports

Change-Id: I66d8de5441612aaee6b50c6b123f8394efd9d665
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/392461
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Samuel Rawlins <[email protected]>

Author: srawlins

pkg/linter/lib/src/test_utilities/lint_driver.dart

@@ -14,9 +14,8 @@ import 'package:analyzer/src/generated/engine.dart' show AnalysisEngine;
 // ignore: implementation_imports
 import 'package:analyzer/src/lint/io.dart';
 
-import 'linter_options.dart';
-
 import 'analysis_error_info.dart';
+import 'linter_options.dart';
 
 class LintDriver {
   /// The files which have been analyzed so far.  This is used to compute the