Refinement of previous patch: the root type must be used for the image
of enumeration types, because the literal map is attached to the root
type even when derivations are present.
Fixes several ACATS and fixedbugs regressions involving 'Image.
Tested on x86_64-pc-linux-gnu, committed on trunk
gc
This patch fixes the handling of the Ada_2020 attribute Img when applied
to derived types. If the type is private it is necessary to retrieve a
non-private description of the type structure, by using an underlying
view (which crosses the privacy boundary). The underlying view is that
of the base ty
