Fix a self-memcpy which only breaks under Valgrind's memcpy

implementation. Silliness, but it'll be a trivial performance
optimization. This should clear up a failure on the vg_leak bot.

llvm-svn: 195704

llvm/lib/Support/SmallPtrSet.cpp

@@ -218,6 +218,9 @@ SmallPtrSetImpl::SmallPtrSetImpl(const void **SmallStorage, unsigned SmallSize,
 /// CopyFrom - implement operator= from a smallptrset that has the same pointer
 /// type, but may have a different small size.
 void SmallPtrSetImpl::CopyFrom(const SmallPtrSetImpl &RHS) {
+  if (&RHS == this)
+    return;
+
   if (isSmall() && RHS.isSmall())
     assert(CurArraySize == RHS.CurArraySize &&
            "Cannot assign sets with different small sizes");