Imported Upstream version 5.8.0.22

Former-commit-id: df344e34b07851d296efb3e6604c8db42b6f7aa3

mcs/errors/cs8138.cs

@@ -0,0 +1,10 @@
+// CS8138: Do not use `System.Runtime.CompilerServices.TupleElementNamesAttribute' directly. Use the tuple syntax instead
+// Line: 7
+
+using System;
+using System.Runtime.CompilerServices;
+
+[TupleElementNames (new[] { "a", "b" })]
+public class C
+{
+}