Refactor some code to avoid having :packing depend on :operator (which transitively brings in :compute and others); this greatly reduces the deps on the microkernel tests and makes future porting work for microkernels easier.

Refactor some code to avoid having :packing depend on :operator (which transitively brings in :compute and others); this greatly reduces the deps on the microkernel tests and makes future porting work for microkernels easier. #42