C#: Add test cases.

Author: michaelnebel

csharp/ql/test/utils/model-generator/CaptureSummaryModels.expected

@@ -18,6 +18,7 @@
 | Summaries;DerivedClass1Flow;false;ReturnParam1;(System.Int32,System.Int32);Argument[1];ReturnValue;taint |
 | Summaries;DerivedClass2Flow;false;ReturnParam0;(System.Int32,System.Int32);Argument[0];ReturnValue;taint |
 | Summaries;DerivedClass2Flow;false;ReturnParam;(System.Int32);Argument[0];ReturnValue;taint |
+| Summaries;EqualsGetHashCodeNoFlow;false;Equals;(System.Int32);Argument[0];ReturnValue;taint |
 | Summaries;GenericFlow<>;false;AddFieldToGenericList;(System.Collections.Generic.List<T>);Argument[Qualifier];Argument[0].Element;taint |
 | Summaries;GenericFlow<>;false;AddToGenericList<>;(System.Collections.Generic.List<S>,S);Argument[1];Argument[0].Element;taint |
 | Summaries;GenericFlow<>;false;ReturnFieldInGenericList;();Argument[Qualifier];ReturnValue;taint |

csharp/ql/test/utils/model-generator/Summaries.cs

@@ -206,4 +206,28 @@ public static explicit operator OperatorFlow(byte b)
         return new OperatorFlow(b);
     }
 
+}
+
+public class EqualsGetHashCodeNoFlow
+{
+    public readonly bool boolTainted;
+    public readonly int intTainted;
+
+    // No flow summary as this is an override of the Equals method.
+    public override bool Equals(object obj)
+    {
+        return boolTainted;
+    }
+
+    // Flow summary as this is not an override of the object Equals method.
+    public int Equals(int i)
+    {
+        return i;
+    }
+
+    // No flow summary as this is an override of the GetHashCode method.
+    public override int GetHashCode()
+    {
+        return intTainted;
+    }
 }