[Polly] Do not inline dumpIslObj methods. NFC.

Instead of being inline and having a neverCalled() workaround to make it
work in the debugger, define it as a regular exported function.

Also add overloads for the C API types isl_* so it works with managed as
well as unmanaged ISL objects.

GitOrigin-RevId: ec2029f986d8bb80963c1efd9e5024bfe7ac3d30
2 files changed