[polly] [polly] Bound ISL operations during pre-vectorization (PR #143876)

[Michael Kruse via llvm-commits]

================
@@ -574,7 +580,12 @@ ScheduleTreeOptimizer::optimizeBand(__isl_take isl_schedule_node *NodeArg,
   if (OAI->Prevect) {
     // FIXME: Prevectorization requirements are different from those checked by
     // isTileableBandNode.
-    Node = applyPrevectBandOpt(Node);
+    {
+      IslMaxOperationsGuard MaxOpGuard(Node.ctx().get(), ScheduleComputeOut);
----------------
Meinersbur wrote:

This will allow as many operations just for prevectorization of band as for the entire scheduling itself. 

I think it would be better if we could expand the top-level IslMaxOperationsGuard in `runIslScheduleOptimizer` to include post-schedule band optimization

https://github.com/llvm/llvm-project/pull/143876