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
This doesn't reduce the quality of tests, because the flags are still
printed for declarations themselves. We only omit them in references.
However, this makes the tests more compatible with non-JVM backends
(see KT-58605), because flags of referenced stdlib declarations may
differ among target platforms.
Dmitriy Novozhilov