Resort polly builders

Place the fastest builders at the beginning.

git-svn-id: https://llvm.org/svn/llvm-project/zorg/trunk@222097 91177308-0d34-0410-b5e6-96231b3b80d8
Make the Polly CLooG tester a correctness tester

We now only run one iteration on this tester. This frees resources for a
-polly-parallel correctness tester.

We also explicitly specify the backend type used, in preparation to the
upcoming switch to the isl backend.

git-svn-id: https://llvm.org/svn/llvm-project/zorg/trunk@222098 91177308-0d34-0410-b5e6-96231b3b80d8
Add a -polly-parallel tester

This is a fast tester that only verifies correctness.

git-svn-id: https://llvm.org/svn/llvm-project/zorg/trunk@222099 91177308-0d34-0410-b5e6-96231b3b80d8