Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing
Bukkit Changes:
1cb03826 SPIGOT-5900: Re-order Material enum entries to match Minecraft's order
fdd705db #507: Add hasDiscoveredRecipe() and getDiscoveredRecipes()
CraftBukkit Changes:
551e770f5 SPIGOT-5900: Add test for the order of Material enum entries
8297676c2#682: Add hasDiscoveredRecipe() and getDiscoveredRecipes()