Imported Upstream version 3.8.0

Former-commit-id: 6a76a29bd07d86e57c6c8da45c65ed5447d38a61

mcs/errors/cs4029.cs

@@ -0,0 +1,19 @@
+// CS4029: Cannot return an expression of type `void'
+// Line: 15
+
+using System;
+using System.Threading.Tasks;
+
+class C
+{
+	static void Foo<T> (Func<Task<T>> f)
+	{
+	}
+
+	static void Main ()
+	{
+		Foo (async () => {
+			return await Task.Factory.StartNew (() => { });
+		});
+	}
+}