isl_pw_*_restrict_domain: perform alignment internally
isl_pw_*_restrict_domain: perform alignment internally

Since isl-0.22-54-g20d3574057 (perform parameter alignment
by modifying both arguments to function, Fri Dec 6 16:08:56 2019 +0100),
the alignment has been moved right before every call
to isl_pw_*_restrict_domain_aligned, so it might as well
be performed inside this function (dropping "_aligned" from the name).
This removes some minor code duplication.

Signed-off-by: Sven Verdoolaege <dd860110a62b19214c4ee03aec0abffecb4e86b8@cerebras.net>

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