C#: Fix some qltests.

Author: aschackmull

csharp/ql/test/experimental/CWE-918/RequestForgery.cs

@@ -38,21 +38,3 @@ public async Task<ActionResult> Good(string url)
         }
     }
 }
-// Missing stubs:
-namespace System.Net.Http
-{
-    public class HttpClient
-    {
-        public async Task SendAsync(HttpRequestMessage request) => throw null;
-    }
-
-    public class HttpRequestMessage
-    {
-        public HttpRequestMessage(HttpMethod method, string requestUri) => throw null;
-    }
-
-    public class HttpMethod
-    {
-        public static readonly HttpMethod Get;
-    }
-}

csharp/ql/test/experimental/CWE-918/options

@@ -0,0 +1 @@
+semmle-extractor-options: /r:System.Net.Http.dll

csharp/ql/test/library-tests/dataflow/library/FlowSummaries.expected

@@ -135,21 +135,3 @@ public string ToHtmlString()
         }
     }
 }
-
-namespace System.Net
-{
-    public class HttpListenerResponse
-    {
-        public System.IO.Stream OutputStream => null;
-    }
-
-    class HttpListenerContext
-    {
-        public HttpListenerResponse Response => null;
-    }
-
-    class HttpListener
-    {
-        public HttpListenerContext GetContext() => null;
-    }
-}

csharp/ql/test/library-tests/dataflow/library/FlowSummariesFiltered.expected

@@ -0,0 +1 @@
+semmle-extractor-options: ${testdir}/../../../../resources/stubs/System.Net.cs

csharp/ql/test/query-tests/Security Features/CWE-079/StoredXSS/XSS.cs

@@ -0,0 +1 @@
+semmle-extractor-options: /r:System.Data.Common.dll

csharp/ql/test/query-tests/Security Features/CWE-079/StoredXSS/options

@@ -12,29 +12,6 @@ public interface IDbConnection : System.IDisposable
 
         namespace Common
         {
-            // Generated from `System.Data.Common.DbConnectionStringBuilder` in `System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089`
-            public class DbConnectionStringBuilder : System.Collections.IEnumerable, System.Collections.IDictionary, System.Collections.ICollection
-            {
-                System.Collections.IDictionaryEnumerator System.Collections.IDictionary.GetEnumerator() => throw null;
-                System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() => throw null;
-                bool System.Collections.ICollection.IsSynchronized { get => throw null; }
-                bool System.Collections.IDictionary.Contains(object keyword) => throw null;
-                object System.Collections.ICollection.SyncRoot { get => throw null; }
-                public object this[object keyword] { get => throw null; set => throw null; }
-                public bool IsReadOnly { get => throw null; }
-                public override string ToString() => throw null;
-                public string ConnectionString { get => throw null; set => throw null; }
-                public virtual System.Collections.ICollection Keys { get => throw null; }
-                public virtual System.Collections.ICollection Values { get => throw null; }
-                public virtual bool IsFixedSize { get => throw null; }
-                public virtual int Count { get => throw null; }
-                public virtual void Clear() => throw null;
-                void System.Collections.ICollection.CopyTo(System.Array array, int index) => throw null;
-                void System.Collections.IDictionary.Add(object keyword, object value) => throw null;
-                void System.Collections.IDictionary.Remove(object keyword) => throw null;
-                public void Dispose() => throw null;
-            }
-
             // Generated from `System.Data.Common.DbConnection` in `System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089`
             abstract public class DbConnection : System.IDisposable, System.Data.IDbConnection
             {