Only skip decls with CUSKs with PolyKinds on (fix #16609)
We only skip decls with CUSKs in kcLTyClDecl
with PolyKinds on (see #16609 (closed)).
This patch adds an extra check before kcLTyClDecl
to see if we have PolyKinds
. If so we skip the decls of CUSKs; otherwise we kind-check the whole recursive group.