Adds support for generating curve primtiives avoiding the
use of primtiive restarts. This maixmises geometry performance
when using Metal.
Also ensure that the existing index buffer optimization path is
skipped for indirect draw calls where counts are not known at
submission time.
Authored by Apple: Michael Parkin-White
Pull Request: https://projects.blender.org/blender/blender/pulls/109972
0f39e46914