title: Is there any way to get Members of a type and all subsequent base types?
body: <p>I have an `<a href="https://github.com/dotnet/roslyn/blob/master/src/Compilers/Core/Portable/Symbols/ITypeSymbol.cs" rel="noreferrer">ITypeSymbol</a>' object. If I call <a href="https://github.com/dotnet/roslyn/blob/c4c6acb1036c53b4ad91e2f92609914a29e602cf/src/Compilers/Core/Portable/Symbols/INamespaceOrTypeSymbol.cs#L23" rel="noreferrer">GetMembers</a>, it gives me the members of the current type, not the base. I know I can dig it using BaseType property and have some iterative code to fetch all the properties. </p>
  
  <p>Is there any easier way to fetch all members regardless of level at the inheritance hierarchy?</p>