[libcxx] Fix vector annotator size increase in `vector::insert(pos, count, value)`

Summary:
The size of the vector is being increased by `__n` during the call to `__move_range` and not by 1.
This fixes a test failure in `containers/sequences/vector/vector.modifiers/insert_iter_size_value.pass.cpp` when using ASAN.

Reviewers: danalbert, kcc, mclow.lists

Reviewed By: mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D6264

llvm-svn: 222014

libcxx/include/vector

@@ -1861,7 +1861,7 @@ vector<_Tp, _Allocator>::insert(const_iterator __position, size_type __n, const_
             }
             if (__n > 0)
             {
-                __RAII_IncreaseAnnotator __annotator(*this);
+                __RAII_IncreaseAnnotator __annotator(*this, __n);
                 __move_range(__p, __old_last, __p + __old_n);
                 __annotator.__done();
                 const_pointer __xr = pointer_traits<const_pointer>::pointer_to(__x);