Merge to upstream r226192.

Change-Id: Id459c8ce0d7dec371ff4d064ee2c71f6b7178e63

test/std/strings/basic.string/string.modifiers/string_assign/rv_string.pass.cpp

@@ -13,6 +13,7 @@
 //   assign(basic_string<charT,traits>&& str);
 
 #include <string>
+#include <utility>
 #include <cassert>
 
 #include "min_allocator.h"

test/std/strings/basic.string/string.nonmembers/string_op+/char_string.pass.cpp

@@ -18,6 +18,7 @@
 //   operator+(charT lhs, basic_string<charT,traits,Allocator>&& rhs);
 
 #include <string>
+#include <utility>
 #include <cassert>
 
 #include "min_allocator.h"

test/std/strings/basic.string/string.nonmembers/string_op+/pointer_string.pass.cpp

@@ -18,6 +18,7 @@
 //   operator+(const charT* lhs, basic_string<charT,traits,Allocator>&& rhs);
 
 #include <string>
+#include <utility>
 #include <cassert>
 
 #include "min_allocator.h"

test/std/strings/basic.string/string.nonmembers/string_op+/string_char.pass.cpp

@@ -18,6 +18,7 @@
 //   operator+(basic_string<charT,traits,Allocator>&& lhs, charT rhs);
 
 #include <string>
+#include <utility>
 #include <cassert>
 
 #include "min_allocator.h"

test/std/strings/basic.string/string.nonmembers/string_op+/string_pointer.pass.cpp

@@ -18,6 +18,7 @@
 //   operator+(basic_string<charT,traits,Allocator>&& lhs, const charT* rhs);
 
 #include <string>
+#include <utility>
 #include <cassert>
 
 #include "min_allocator.h"

test/std/strings/basic.string/string.nonmembers/string_op+/string_string.pass.cpp

@@ -30,6 +30,7 @@
 //             const basic_string<charT,traits,Allocator>&& rhs);
 
 #include <string>
+#include <utility>
 #include <cassert>
 
 #include "min_allocator.h"