"Could not resolve type reference" for some iterator methods in VS2015

[billings7]

Any iterator methods which are explicitly implemented from an interface, and the interface contains multiple generic type arguments, causes a "Could not resolve type reference" error in the re-writer when built in Visual Studio 2015.
For example:

public class TestYield : IEnumerable<Tuple<int, int>>
{
    IEnumerator<Tuple<int, int>> IEnumerable<Tuple<int, int>>.GetEnumerator()
    {
        yield break;
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        yield break;
    }
}

fails with Could not resolve type reference: [TestContracts]TestContracts.TestYield.<System-Collections-Generic-IEnumerable<System-Collections-Generic-KeyValuePair<System-Int32\,System-Int32>>-GetEnumerator>d__0.

The root cause of this is the type name parser used by the re-writer to read attributes does not support reading type names with escaped characters. The Rosyln compiler is adding an IteratorStateMachineAttribute to the method pointing to a type with the name <System-Collections-Generic-IEnumerable<System-Collections-Generic-KeyValuePair<System-Int32,System-Int32>>-GetEnumerator>d__0, and the comma in the generic arguments gets escaped with a backslash in the IL.

Pull request incoming.

[SergeyTeplyakov]

Double checked that fix worked. Closing the issue.

P.S. Still trying to add an unit test for this case...