Just do the same thing you used to do, but w/o annotating as AlternateSignature. See https://github.com/nikhilk/scriptsharp/blob/cc/tests/TestCases/Member/Overloads/Code.cs
See same test cases.
See https://github.com/nikhilk/scriptsharp/blob/cc/History.txt for on-going list of changes. As you'll observe from here, the test cases also help illustrate various features.
Hope that helps.