Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size.

llvm-svn: 216158
diff --git a/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp b/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
index 2d9223f..dc8cafa 100644
--- a/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
@@ -1714,7 +1714,7 @@
 static bool IsSafeAndProfitableToMove(bool isLd, unsigned Base,
                                       MachineBasicBlock::iterator I,
                                       MachineBasicBlock::iterator E,
-                                      SmallPtrSet<MachineInstr*, 4> &MemOps,
+                                      SmallPtrSetImpl<MachineInstr*> &MemOps,
                                       SmallSet<unsigned, 4> &MemRegs,
                                       const TargetRegisterInfo *TRI) {
   // Are there stores / loads / calls between them?