This fixes strict weak ordering checks violations from #155348 when
running these two tests:
mlir/test/Dialect/OpenMP/omp-offload-privatization-prepare.mlir
mlir/test/Dialect/OpenMP/omp-offload-privatization-prepare-by-value.mlir
Sample error:
/stable/src/libcxx/include/__debug_utils/strict_weak_ordering_check.h:50: libc++ Hardening assertion !__comp(*__first + __a), *(__first + __b)) failed: Your comparator is not a valid strict-weak ordering
This is because (x < x) should be false, not true, to meet the
irreflexibility property. (Note that .dominates(x, x) returns true.)
I'm afraid that even after this commit we can't guarantee a strict weak
ordering, because we can't guarantee transitivity of equivalence by
sorting with a strict dominance function. However the tests are not
failing anymore, and I am not at all familiar with this code so I will
leave this concern up to the original author for consideration. (Ideas
without any further context: I would consider a topological sort or
walking a dominator tree.)
Reference on std::sort and strict weak ordering:
https://danlark.org/2022/04/20/changing-stdsort-at-googles-scale-and-beyond/
fb925b5244