For IrProperty, IrSimpleFunction we need to pass information about
original declaration to JVM_IR codegen. Instead of descriptors, use
the attributeOwnerId field.
Unfortunately this requires a lot of boilerplate, but is a requirement
for transforming the main IR element hierarchy interfaces
(IrDeclaration, IrClass, ...) to classes.
This will help to reduce boilerplate after making the latter classes.
Without this change, IrFunctionCommonImpl would not be able to be a
class because it would introduce a diamond class hierarchy, and thus
that would require copying all its contents to IrFunctionImpl and
IrFakeOverrideFunctionImpl.
Alexander Udalov