isl_printer_print_map: do not print local variables with explicit representation
isl_printer_print_map: do not print local variables with explicit representation

The explicit representations are now used directly inside the constraints
such that the local variables are no longer needed.
Not printing local variables with an explicit representation is also
more in line with expectations, especially in case quantifier elimination
has been applied.  That is, after quantifier elimination, the output
should no longer contain any quantified variables.

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

PollyLabs/isl,inducer/isl-mirror,PollyLabs/isl,PollyLabs/isl,Meinersbur/isl,PollyLabs/isl,tobig/isl,inducer/isl-mirror,UBERTC/isl,tobig/isl,BenzoSM/isl,Distrotech/isl,nicolasvasilache/isl,nicolasvasilache/isl,UBERTC/isl,BenzoSM/isl,tobig/isl,BenzoSM/isl,BenzoSM/isl,Distrotech/isl,tobig/isl,Distrotech/isl,nicolasvasilache/isl,Distrotech/isl,inducer/isl-mirror,nicolasvasilache/isl,inducer/isl-mirror,PollyLabs/isl,inducer/isl-mirror,BenzoSM/isl,Meinersbur/isl,Distrotech/isl,nicolasvasilache/isl,Meinersbur/isl,UBERTC/isl,UBERTC/isl,Meinersbur/isl