Add KHR_mesh_primitive_restart#2569

donmccurdy wants to merge 3 commits intoKhronosGroup:mainKhronosGroup/glTF:mainfrom

CesiumGS:donmccurdy/KHR_mesh_primitive_restartCesiumGS/glTF:donmccurdy/KHR_mesh_primitive_restartCopy head branch name to clipboard