Add Symbol.info to Quotes.reflect

[nicolasstucki]

We seem to have missed this method. Users have been using sym.tree.tpe or sym.tree.tpt which is not ideal.

[nicolasstucki]

To support this we also need to add ClassInfo

[smarter]

Can this be closed since #11664 was closed given we already have memberInfo?

[nicolasstucki]

Yes, I thought I had already closed it.