Imported Upstream version 5.14.0.78

Former-commit-id: 3494343bcc9ddb42b36b82dd9ae7b69e85e0229f

mcs/class/System/corefx/NameValueCollection.cs

@@ -0,0 +1,17 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Runtime.Serialization;
+using System.Text;
+
+namespace System.Collections.Specialized
+{
+    partial class NameValueCollection
+    {
+        // Allow internal extenders to avoid creating the hashtable/arraylist.
+        internal NameValueCollection (DBNull dummy) : base (dummy)
+        {
+        }
+    }
+}