properly initialize dim3 variables of length zero
properly initialize dim3 variables of length zero

Before this commit, they were being printed as function declarations.

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

Meinersbur/ppcg,Meinersbur/ppcg,nicolasvasilache/ppcg,nicolasvasilache/ppcg