* [Yoga] Implement ASYogaLayoutSpec, an experimental alternative to full-tree integration.
This approach allows us to avoid any ASDisplayNode.mm integration points.
However, it is not yet proven to be possible to achieve correctness with this approach.
The entry point (to start calculating), and the measurement function inputs, lack
the full expressiveness of ASSizeRange; we need to make sure that workarounds like
using style.minSize are successful in simulating the behavior of a full Yoga tree.
* [Yoga] Fix file comments, move towards <ASLayoutElement> support.
* [Yoga] Important fix for simplified, non-contiguous Yoga integration.
* [Yoga] Complete implementation of manual memory management (__bridge_transfer, YGNodeFree)
* Need to check availability before use of macros.
* Get rid of PCH and enforce macro definition.
* Remove prefix
* Switch to global warning instead, much better.
* no message
* Go further
* Make the symbols public so that apps actually build
* Move ASAvailability into the umbrella header
* Remove duplicate define
* Put the file back where it was in the list
* Revert "Put the file back where it was in the list"
This reverts commit 6a80c15b5b5efe5ff39812a018114e8bdc1dc0cf.
