C#: Base tests for CWE-020 on stubs.

Author: michaelnebel

csharp/ql/test/query-tests/Security Features/CWE-020/options

@@ -1 +1,3 @@
-semmle-extractor-options: /r:${testdir}/../../../resources/assemblies/System.Web.dll /r:${testdir}/../../../resources/assemblies/System.Web.ApplicationServices.dll /r:${testdir}/../../../resources/assemblies/System.Data.dll /r:System.Text.RegularExpressions.dll /r:System.Collections.Specialized.dll /r:System.Data.Common.dll /r:System.Security.Cryptography.X509Certificates.dll /r:System.Runtime.InteropServices.dll
+semmle-extractor-options: /nostdlib /noconfig
+semmle-extractor-options: --load-sources-from-project:${testdir}/../../../resources/stubs/_frameworks/Microsoft.NETCore.App/Microsoft.NETCore.App.csproj
+semmle-extractor-options: ${testdir}/../../../resources/stubs/System.Web.cs

csharp/ql/test/resources/stubs/System.Web.cs

@@ -156,6 +156,7 @@ public class HttpRequest
     public class HttpResponse
     {
         public void Write(object o) { }
+        public void Write(string s) { }
         public void WriteFile(string s) { }
         public HttpCookieCollection Cookies => null;
         public void AddHeader(string name, string value) { }