[mcs] fails to compile code with Tuple

[lewurm]

Steps to Reproduce

using System.Linq;

class Program {
    public static int Main () {
        var l = (from f in (typeof (Program)).GetFields() select (name: f.Name, offset: 0)).ToList();

        return 0;
    }
}

Current Behavior

$ mcs hmm.cs
Compilation failed: 1 error(s), 0 warnings

Expected Behavior

$ csc hmm.cs
Microsoft (R) Visual C# Compiler version 2.6.0.62309 (d3f6b8e7)
Copyright (C) Microsoft Corporation. All rights reserved.

no failure.

Version Used:
master

due to this, mcs can't compile mono/tests/sizeof-empty-structs.cs

/cc #7722

[luhenry]

@lewurm is it acceptable for now to modify sizeof-empty-structs.cs to not use tuples? This is in no way the fix, but that would be to unblock #7722