Summary:
This can be marked in fixtures to skip a test without commenting it out. We add one more usage of this.
The same functionality existed (unused) before for `experiments`, which I changed to `data-experiments`.
Formatting of JS tests changed to be closer to what Prettier would output, and to remove usage of `Yoga.UNDEFINED` which doesn't existi and just resolves to `undefined` (this is converted to NaN by the wrapper layer).
Differential Revision: D45723003
fbshipit-source-id: c014e1695d90fcb44d62f6a636ddbb0d86ec6eff