Automatic merge from submit-queue
WIP - Handle map[]struct{} in DeepCopy
Deep copy was not properly handling the empty struct case we use for Sets.
@lavalamp I need your expertise when you have some time - the go2idl parser is turning sets.String into the following tree:
type: sets.String kind: Alias
underlying: map[string]sets.Empty kind: Map
key: string kind: Builtin
elem: set.Empty kind: Struct
^
should be Alias
Looking at tc.Named, I'm not sure what the expected outcome would be and why you flatten there.