isl_space_can_uncurry: implement with isl_space_range_is_wrapping
isl_space_can_uncurry: implement with isl_space_range_is_wrapping

Besides simplifying the code, this corrects the semantics of this
function. For set spaces with wrapped spaces it now always returns
isl_bool_false, instead of isl_bool_true. This is correct, as set spaces
cannot be uncurried.

As a minor side effect, this commit removes implicit boolean conversions.

Signed-off-by: Tobias Grosser <059b8b880f8441509ec8a65b50b4c6ae74ebea76@grosser.es>
Signed-off-by: Sven Verdoolaege <235c10dd23b819f81cdc9756a251746bc184cab6@gmail.com>

Meinersbur/isl,Meinersbur/isl,Meinersbur/isl,Meinersbur/isl