C#: Add dummy type sizes for the list pattern expressions kinds.

Author: michaelnebel

csharp/ql/lib/semmlecode.csharp.dbscheme.stats

@@ -948,6 +948,14 @@
             <k>@with_expr</k>
             <v>101</v>
         </e>
+        <e>
+            <k>@list_pattern_expr</k>
+            <v>0</v>
+        </e>
+        <e>
+            <k>@slice_pattern_expr</k>
+            <v>0</v>
+        </e>
         <e>
             <k>@xmldtd</k>
             <v>40</v>