Suppress a few analysis warnings in the analyzer codebase.

pkg/analysis_server/test/stress/utilities/server.dart

Index: pkg/analysis_server/test/stress/utilities/server.dart
diff --git a/pkg/analysis_server/test/stress/utilities/server.dart b/pkg/analysis_server/test/stress/utilities/server.dart
index 88a44ce9a08e44dc3ea026ea51a31eccd91d39f0..08beaa04e4adae56cc17a30e2cd402f1b03cfc73 100644
--- a/pkg/analysis_server/test/stress/utilities/server.dart
+++ b/pkg/analysis_server/test/stress/utilities/server.dart
@@ -190,11 +190,6 @@ class Server {
   List<String> _analysisRootIncludes = <String>[];
 
   /**
-   * The analysis roots that are excluded.
-   */
-  List<String> _analysisRootExcludes = <String>[];
-
-  /**
    * A list containing the paths of files for which an overlay has been created.
    */
   List<String> filesWithOverlays = <String>[];
@@ -448,7 +443,6 @@ class Server {
       List<String> included, List<String> excluded,

[Brian Wilkerson, 2017/02/11 22:27:36]

Sigh. I was planning on using the excludes information too, as soon as I could
get back to finishing the stress test. But if you're going to remove the field,
then you might as well remove the parameter too.

       {Map<String, String> packageRoots}) {
     _analysisRootIncludes = included;
-    _analysisRootExcludes = excluded;
     var params = new AnalysisSetAnalysisRootsParams(included, excluded,
             packageRoots: packageRoots)
         .toJson();