[polly] Fix non-determinism in IslNodeBuilder.
The iteration order of OutsideLoopIterations matters for
IslNodeBuilder::getReferencesInSubtree, which inserts the values from
the map into a SetVector, which is eventually used to construct the
type of the context for parallel loops.
@@ -160,7 +160,7 @@ protected:
///
/// This map provides for a given loop a llvm::Value that contains the current
/// loop iteration.
- LoopToScevMapT OutsideLoopIterations;
+ MapVector<const Loop *, const SCEV *> OutsideLoopIterations;
// This maps an isl_id* to the Value* it has in the generated program. For now
// on, the only isl_ids that are stored here are the newly calculated loop
