Previously fir2ir created real IR properties some getter and setter for
such references, which lead to the situation that there might be a
unbound fake override for synthetic property which wasn't stored in
declaration storage (and code in FakeOverrideGenerator was a hack
to cover this case)
In the same time K1 creates fake property for such cases, which is stored
in IrPropertyReference along with original get... and set... functions
as getter and setter of reference. And in this commit K2 does the same thing
^KT-61637
Dmitriy Novozhilov
36cb869ac2