isl_map_intersect: add missing isl_map_unmark_normalized
isl_map_intersect: add missing isl_map_unmark_normalized

When a single constraint gets added to a convex map,
the intersection is performed in-place.
Since a constraint gets added to the basic map
without a subsequent normalization of this basic map,
the containing map can no longer be assumed to be normalized.

Signed-off-by: Sven Verdoolaege <235c10dd23b819f81cdc9756a251746bc184cab6@gmail.com>

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