[polly] polly: Fix files that contain Python 3 SyntaxErrors (PR #124424)

[Michael Kruse via llvm-commits]

Meinersbur wrote:

Yes, the dependencies may not be obvious. 
 * imath is a library with the upstream location at https://github.com/creachadair/imath/
 * isl is a library that uses imath using git submodules. isl's public website is https://libisl.sourceforge.io/ and the upstream  location is https://repo.or.cz/w/isl.git. That site doesn't know how to show submodules. See my github mirror instead:  https://github.com/meinersbur/isl
 * Polly depends on isl and just copies isl (and its imath submodule) into the repository. It is not intended to be a fork, so it should be a clean copy of whatever is upstream. Please remove that change from this PR.

https://github.com/llvm/llvm-project/pull/124424