drop isl_set_lower_bound_dim
drop isl_set_lower_bound_dim

This function was introduced in 333dfc8 (add isl_set_lower_bound_dim,
Fri Sep 26 10:34:15 2008 +0200) and then hidden in 6272dbd (deprecate
isl_int, Fri May 3 18:31:59 2013 +0200) without being used internally.

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

PollyLabs/isl,tobig/isl,Meinersbur/isl,PollyLabs/isl,PollyLabs/isl,inducer/isl-mirror,nicolasvasilache/isl,nicolasvasilache/isl,inducer/isl-mirror,Meinersbur/isl,inducer/isl-mirror,tobig/isl,tobig/isl,Meinersbur/isl,tobig/isl,inducer/isl-mirror,PollyLabs/isl,Meinersbur/isl,nicolasvasilache/isl,PollyLabs/isl,nicolasvasilache/isl,inducer/isl-mirror,nicolasvasilache/isl