Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186274 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DependenceAnalysis.cpp b/lib/Analysis/DependenceAnalysis.cpp
index 450dcbc..2057656 100644
--- a/lib/Analysis/DependenceAnalysis.cpp
+++ b/lib/Analysis/DependenceAnalysis.cpp
@@ -2977,7 +2977,7 @@
 bool DependenceAnalysis::propagate(const SCEV *&Src,
                                    const SCEV *&Dst,
                                    SmallBitVector &Loops,
-                                   SmallVector<Constraint, 4> &Constraints,
+                                   SmallVectorImpl<Constraint> &Constraints,
                                    bool &Consistent) {
   bool Result = false;
   for (int LI = Loops.find_first(); LI >= 0; LI = Loops.find_next(LI)) {