Crash when property has a setter but no getter

[oliwennell]

E.g. with the following code:

private int _thing;
public int Thing
{
   set { _thing = value; }
}

In MemberDeclarationSyntaxExtensions.CanInstrumentProperty, the call to accessors.Single(a => a.Kind() == SyntaxKind.GetAccessorDeclaration) will throw an exception