isl_aff.c: pw_aff_aff_on_domain: explicitly insert domain
isl_aff.c: pw_aff_aff_on_domain: explicitly insert domain

This function adds input dimensions to an object living in a set space.
While this happens to work in the current code base, this is technically
incorrect.  First change the object to live in a map space.

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

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