IrDeclarationOrigin.FILE_CLASS is used in CallableReferenceLowering to
generate correct declaration owner.
Many reflection tests start to fail with this commit because they are
now treating callable references to top level declarations as Kotlin
symbols and fail because there's no JVM signature for them; this is
fixed in subsequent commits (previously, they worked because without
Kotlin metadata, these files were treated as Java classes)
Alexander Udalov
5c807266f6