Replace std::copy with a back inserter with vector append where feasible

All of the cases were just appending from random access iterators to a
vector. Using insert/append can grow the vector to the perfect size
directly and moves the growing out of the loop. No intended functionalty
change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230845 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/SROA.cpp

@@ -247,7 +247,7 @@ public:
   /// hold.
   void insert(ArrayRef<Slice> NewSlices) {
     int OldSize = Slices.size();
-    std::move(NewSlices.begin(), NewSlices.end(), std::back_inserter(Slices));
+    Slices.append(NewSlices.begin(), NewSlices.end());
     auto SliceI = Slices.begin() + OldSize;
     std::sort(SliceI, Slices.end());
     std::inplace_merge(Slices.begin(), SliceI, Slices.end());