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

llvm-svn: 215868
diff --git a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
index 213889d..137d3ad 100644
--- a/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/llvm/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -575,7 +575,7 @@
 static unsigned
 iterateChainSucc(AliasAnalysis *AA, const MachineFrameInfo *MFI,
                  SUnit *SUa, SUnit *SUb, SUnit *ExitSU, unsigned *Depth,
-                 SmallPtrSet<const SUnit*, 16> &Visited) {
+                 SmallPtrSetImpl<const SUnit*> &Visited) {
   if (!SUa || !SUb || SUb == ExitSU)
     return *Depth;