Add Alignment Property

[fpedd]

• Add the alignment property to the primitive.
• Add an alignment checking utility function: A way for allocators to quickly check if any allocations have non-trivial alignment requirements, so they can error out early if they don't support them
• Post-hoc alignment enforcement function: Add a function that takes already-allocated allocations and adjusts offsets to satisfy alignment, even if it creates gaps/increases memory use.
• Port allocators over to support alignment

Open questions:

• Where do alignments belong (Memory, Pool, Allocation)?
• Should we enforce a power-of-two constraint?

Reference: https://gist.github.com/fpedd/6cf169487e994eb63e54e535f4f3cea9