C#: Add DB upgrade and downgrade scripts.

Author: michaelnebel

csharp/downgrades/97da4e8c5750e07c4f7c8a366b21060e05ecd5ed/cil_type_annotation.ql

@@ -0,0 +1,11 @@
+class AnnotatedElement extends @cil_has_type_annotation {
+  string toString() { none() }
+}
+
+class Field extends @cil_field {
+  string toString() { none() }
+}
+
+from AnnotatedElement element, int annotation
+where cil_type_annotation(element, annotation) and not element instanceof Field
+select element, annotation