When computing the conversion type for a type operator call, the
argument needs to be fully unwrapped before getting the resolved type.
This avoids the situation when the argument is a when-subject and the
assumed original type is not correct. Before, only smart-casts were
unwrapped, and this change will also unwrap when-subjects (as well as a
few other FirExpressions).
^KT-62114 Fixed
Brian Norman