isl_aff.c: map_from_pw_aff: rename "dim" variable to "space"
isl_aff.c: map_from_pw_aff: rename "dim" variable to "space"

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

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