C#: Update expected test output.

Author: michaelnebel

csharp/ql/test/library-tests/parameters/ParameterModifiers.expected

@@ -4,10 +4,9 @@ parameterModifier
 | ParameterModifiers.cs:8:31:8:32 | p3 | 2 |
 | ParameterModifiers.cs:13:31:13:32 | p4 | 1 |
 | ParameterModifiers.cs:15:36:15:37 | p5 | 3 |
-| ParameterModifiers.cs:17:40:17:41 | p6 | 0 |
+| ParameterModifiers.cs:17:40:17:41 | p6 | 6 |
 parameterIsValue
 | ParameterModifiers.cs:5:27:5:28 | p1 |
-| ParameterModifiers.cs:17:40:17:41 | p6 |
 parameterIsIn
 | ParameterModifiers.cs:6:30:6:31 | p2 |
 parameterIsOut
@@ -16,3 +15,5 @@ parameterIsRef
 | ParameterModifiers.cs:13:31:13:32 | p4 |
 parameterIsParams
 | ParameterModifiers.cs:15:36:15:37 | p5 |
+parameterIsReadonlyRef
+| ParameterModifiers.cs:17:40:17:41 | p6 |