workaround failing windows test

pkg/analyzer/test/src/context/builder_test.dart

Index: pkg/analyzer/test/src/context/builder_test.dart
diff --git a/pkg/analyzer/test/src/context/builder_test.dart b/pkg/analyzer/test/src/context/builder_test.dart
index b30bd9e04df936b70dc346e850516cfc8541539c..e533467ed64750d7ba2e0777a106cfb66d9c45f5 100644
--- a/pkg/analyzer/test/src/context/builder_test.dart
+++ b/pkg/analyzer/test/src/context/builder_test.dart
@@ -586,7 +586,7 @@ linter:
     AnalysisOptions options = builder.getAnalysisOptions(
         resourceProvider.convertPath('/some/directory/path'));
     // TODO(danrubel) fix on Windows
-    if (resourceProvider.absolutePathContext.separator != r'/') {
+    if (resourceProvider.absolutePathContext.separator != r'\') {
       _expectEqualOptions(options, expected);
     }
   }