Merge pull request #51 from xamarin/olegoid/altool-feature-support

[vsts-938452] Add `altool` feature support

Xamarin.MacDev/MonoTouchSdk.cs

@@ -423,5 +423,9 @@ namespace Xamarin.MacDev
 		public bool SupportsArm64_32 {
 			get { return SupportsFeature ("arm64_32"); }
 		}
+
+		public bool SupportsAltool {
+			get { return SupportsFeature ("altool"); }
+		}
 	}
 }