[clang] [polly] [llvm] [polly][ScheduleOptimizer] Fix long compile time(hang) reported in polly (PR #75141)

[Karthika Devi C via cfe-commits]

kartcq wrote:

Thanks for your comments @efriedma-quic 

**> The isl_options_set_on_error thing still seems like an issue; there's a path to restore on_error, but it doesn't run if the quota is hit.**
Your concern makes sense. I have removed the early return there.

**> Do we actually need to explicitly check hasQuotaExceeded() at all? If there's an error, the schedule should be null, and there's already a check for `if (Schedule.is_null())`.**
I will still choose to keep hasQuotaExceeded() function to add a debug print indicating the reason for bailout as quota exceeded.


https://github.com/llvm/llvm-project/pull/75141