Merge pull request #7406 from michaelnebel/csharp-system-threading-csv

C#: Convert more flow summaries to CSV format.

Author: michaelnebel

csharp/ql/lib/semmle/code/csharp/dataflow/ExternalFlow.qll

@@ -100,6 +100,8 @@ private module Frameworks {
   private import semmle.code.csharp.frameworks.system.IO
   private import semmle.code.csharp.frameworks.system.io.Compression
   private import semmle.code.csharp.frameworks.system.Xml
+  private import semmle.code.csharp.frameworks.system.threading.Tasks
+  private import semmle.code.csharp.frameworks.system.runtime.CompilerServices
 }
 
 /**