[Bug tree-optimization/66117] GCC can not compile when graphite is enabled, due to missing isl headers.

[pbeeler80 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66117

--- Comment #3 from Paul Beeler <pbeeler80 at gmail dot com> ---
Final patch will work to be the most minimal for changes and HAVE_isl
https://github.com/SaberMod/GCC_SaberMod/commit/114e4e9470260a839d55aad2421fb646af12697b