add missing annotations to isl_basic_map_drop_redundant_divs
add missing annotations to isl_basic_map_drop_redundant_divs

These annotations prevent some memory leak warnings from being raised while
performing static analysis.

Signed-off-by: Malhar Thakkar <175583fe9ae8f947aec83236cb1baf9d3d301973@gmail.com>
Signed-off-by: Sven Verdoolaege <235c10dd23b819f81cdc9756a251746bc184cab6@gmail.com>

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