Apparently type annotations ('kotlin.extension' in particular) are lost
somewhere in control-flow values processor at the moment, so types may not be
as precise as they were when functions and extension functions had different
classifiers.
This test presumably only affects IDE functionality like 'Extract Method' in a
way that it will suggest a slightly incorrect function type for the parameter
of an extracted method. An issue is to be reported and fixed later upon demand
Alexander Udalov