[polly] Change SmallPtrSet which is being iterated to SmallSetVector in ScopInfo.h

[mgrang]

Summary

This will avoid non-deterministic iteration order.

polly/trunk/include/polly/ScopInfo.h

public:
 
   /// Return the base pointer.
   Value *getBasePtr() const { return BasePtr; }
 
   /// For indirect accesses return the origin SAI of the BP, else null.
   const ScopArrayInfo *getBasePtrOriginSAI() const { return BasePtrOriginSAI; }
 
   /// The set of derived indirect SAIs for this origin SAI.
-  const SmallPtrSetImpl<ScopArrayInfo *> &getDerivedSAIs() const {
+  const SmallSetVector<ScopArrayInfo *, 2> &getDerivedSAIs() const {
     return DerivedSAIs;
   }
 
   /// Return the number of dimensions.
   unsigned getNumberOfDimensions() const {
     if (Kind == MK_PHI || Kind == MK_ExitPHI || Kind == MK_Value)
       return 0;
     return DimensionSizes.size();
private:
   void addDerivedSAI(ScopArrayInfo *DerivedSAI) {
     DerivedSAIs.insert(DerivedSAI);
   }
 
   /// For indirect accesses this is the SAI of the BP origin.
   const ScopArrayInfo *BasePtrOriginSAI;
 
   /// For origin SAIs the set of derived indirect SAIs.
-  SmallPtrSet<ScopArrayInfo *, 2> DerivedSAIs;
+  SmallSetVector<ScopArrayInfo *, 2> DerivedSAIs;
 
   /// The base pointer.
   AssertingVH<Value> BasePtr;
 
   /// The canonical element type of this array.
   ///
   /// The canonical element type describes the minimal accessible element in
   /// this array. Not all elements accessed, need to be of the very same type,