C#: More implicit ToString examples.

Author: michaelnebel

csharp/ql/test/library-tests/implicittostring/implicitToString.cs

@@ -10,6 +10,10 @@ public override string ToString()
         }
     }
 
+    public class Container2 : Container { }
+
+    public class Container3 { }
+
     public class FormattableContainer : IFormattable
     {
         public string ToString(string format, IFormatProvider formatProvider)
@@ -40,5 +44,11 @@ public void M()
         y = "Hello" + formattableContainer; // Implicit call to ToString().
         y = $"Hello {formattableContainer}"; // Implicit call to ToString(string, IFormatProvider). We don't handle this.
         y = $"Hello {formattableContainer:D}"; // Implicit call to ToString(string, IFormatProvider). We don't handle this.
+
+        var container2 = new Container2();
+        y = "Hello" + container2; // Implicit Container.ToString call.
+
+        var container3 = new Container3();
+        y = "Hello" + container3; // Implicit Object.ToString call.
     }
 }

csharp/ql/test/library-tests/implicittostring/implicitToString.expected

@@ -1,4 +1,4 @@
-| implicitToString.cs:31:27:31:35 | call to method ToString |
-| implicitToString.cs:33:22:33:30 | call to method ToString |
-| implicitToString.cs:35:22:35:30 | call to method ToString |
-| implicitToString.cs:40:23:40:42 | call to method ToString |
+| implicitToString.cs:35:27:35:35 | call to method ToString |
+| implicitToString.cs:37:22:37:30 | call to method ToString |
+| implicitToString.cs:39:22:39:30 | call to method ToString |
+| implicitToString.cs:44:23:44:42 | call to method ToString |