Remove unused constexpr
Remove unused constexpr

Summary:
@public

Removes unused constexpr variables from YGStyle. Not polluting the global namespace is a good thing.

Reviewed By: SidharthGuglani

Differential Revision: D13816817

fbshipit-source-id: e4c27a8f2de466ccb759bbe52cdaea6fe451b961

facebook/css-layout,facebook/yoga,facebook/css-layout,facebook/css-layout,facebook/css-layout,facebook/yoga,facebook/yoga,facebook/yoga,facebook/yoga,facebook/yoga,facebook/yoga,facebook/css-layout,facebook/css-layout,facebook/css-layout,facebook/yoga,facebook/yoga,facebook/yoga,facebook/css-layout,facebook/css-layout