[flang] Align runtime info and lowering regarding passing ABIs (#81166)

Runtime derived type info contains information to tell the runtime if
some argument in a user defined assignment must be passed with a
descriptor or not. This information was not properly build, it would
tell the runtime that TARGET argument must be passed via descriptor,
which is incorrect.

Share the logic between lowering and runtime info generation to
determine if an argument must be passed by descriptor or not.