Previously, creating a declaration with Fir2IrCallableDeclarationsGenerator/
Fir2IrClassifiersGenerator didn't guarantee that this declaration will
be actually added to the list of parent class/file declarations, which
lead to situations when FIR2IR created some declarations in the air
(mostly fake-overrides)
The header klib is supposed to only contain the public abi of the module
similar to jvm-abi-gen. It is intended to be used as a dependency for other
klib compilations instead of the full klib for compilation avoidance.
^KT-60807
Johan Bay