A suspend stub for the abstract function
may be created in the context of the child function.
If on an incremental rebuild the stub is created from
the parent context (e.g. a file with the child is not modified),
the resulting LoweredDeclarationSignature will be different.
It will lead to a broken cross-module reference and broken JS code.
Therefore it is required to wrap the creation routine
into StageController::restrictTo() explicitly.
^KT-54934 Fixed
Alexander Korepanov