Add delinearization testcase for ivs that do not follow the loop order

This is a test case that is currently failing, but that should start working
with an upcoming version of our delinearization pass.

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@207678 91177308-0d34-0410-b5e6-96231b3b80d8