Imported Upstream version 5.2.0.175

Former-commit-id: bb0468d0f257ff100aa895eb5fe583fb5dfbf900

mcs/tests/test-async-90.cs

@@ -0,0 +1,35 @@
+using System.Threading.Tasks;
+
+static class Y
+{
+    public static string ExCall (this X x)
+    {
+        return null;
+    }
+}
+
+class X
+{
+    static X Test (object o)
+    {
+        return null;
+    }
+
+    X Prop { get; set;}
+
+    X Call ()
+    {
+        return null;
+    }
+
+    public static void Main ()
+    {
+        var x = new X ();
+        x.Test ().Wait ();
+    }
+
+    async Task Test ()
+    {
+        var x = X.Test (await Task.FromResult (1))?.Prop?.ExCall ();
+    }
+}