isl_tab_pip.c: move common parts of isl_*_free functions to isl_sol_free
isl_tab_pip.c: move common parts of isl_*_free functions to isl_sol_free

This is a minor clean-up.  As a result of this clean-up, the isl_*_free
function can no longer be called directly since they do not free
some common fields or the structure itself.

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

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