This origin was set somewhat arbitrarily.
It actually only makes sense for `IrCall`s to property getters.
There were no places in lowerings that checked `IrGetField` expressions
for this origin value.
^KT-62500 Fixed
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.