Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/errors/CS0571-3-lib.cs

@@ -0,0 +1,12 @@
+// Testcase for bug #59980
+
+namespace Test {
+	public abstract class C0 {
+		public abstract int foo { get; }
+	}
+	public abstract class C1 : C0 {
+	}
+	public class C2 : C1 {
+		public override int foo { get { return 0; } }
+	}
+}