complibs: add ISL

ISL is used by gcc-4.8 onward for GRAPHITE, so is also used as
backend for CLooG 0.18.0 onward.

Reported-by: "Plotnikov Dmitry" <leitz@ispras.ru>
[Dmitry did a preliminray patch to add ISL, which this one is inspired from]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 python

 import sys

 sys.path.insert(0, '@@PREFIX@@/share/gcc-@@VERSION@@/python')

 from libstdcxx.v6.printers import register_libstdcxx_printers

 register_libstdcxx_printers (None)

 end