add enableAsync to analysis option file flags

pkg/analysis_server/lib/src/status/get_handler.dart

Index: pkg/analysis_server/lib/src/status/get_handler.dart
diff --git a/pkg/analysis_server/lib/src/status/get_handler.dart b/pkg/analysis_server/lib/src/status/get_handler.dart
index 0f4fc1590013186061e4117e852c0e6f98d9da2d..0cc6ed402b590e63e73f74edce1748dc91f31a2b 100644
--- a/pkg/analysis_server/lib/src/status/get_handler.dart
+++ b/pkg/analysis_server/lib/src/status/get_handler.dart
@@ -1253,6 +1253,8 @@ class GetHandler {
               buffer, 'Analyze functon bodies', options.analyzeFunctionBodies);
           _writeOption(buffer, 'Cache size', options.cacheSize);
           _writeOption(
+            buffer, 'Enable async support', options.enableAsync);

[Brian Wilkerson, 2016/01/08 18:51:35]

not formatted?

+          _writeOption(
               buffer, 'Enable generic methods', options.enableGenericMethods);
           _writeOption(buffer, 'Enable strict call checks',
               options.enableStrictCallChecks);