[libcxx] [test] Include the iterator header for back_inserter.

[STL_MSFT]

Summary

Code was recently added to this test that uses std::back_inserter. Therefore, the header <iterator> must be included. (MSVC's STL demands this, as we don't otherwise drag in back_inserter.)

[mclow.lists]

Committed as revision 279453

[STL_MSFT]

This was checked in ages ago.

test/std/containers/associative/map/map.cons/copy_assign.pass.cpp

 // class map
 
 // map& operator=(const map& m);
 
 #include <map>
 #include <cassert>
 #include <vector>
 #include <algorithm>
+#include <iterator>
 
 #include <iostream>
 
 #include "../../../test_compare.h"
 #include "test_allocator.h"
 #include "min_allocator.h"
 
 #if TEST_STD_VER >= 11