surface: Don't inline z_reorder().
surface: Don't inline z_reorder().

Haxe 3.1 doesn't seem to like this anymore, but haven't investigated
further why exactly.

Signed-off-by: aszlig <ee1aa092358634f9c53f01b5a783726c9e21b35a@redmoonstudios.org>

aszlig/hase