[committed] libstdc++: testsuite: Add missing header

[Jonathan Wakely via Gcc-patches]

Tested powerpc64le-linux, pushed to trunk.

-- >8 --

libstdc++-v3/ChangeLog:

        * testsuite/ext/mt_allocator/22309_thread.cc: Include <string>.
---
 libstdc++-v3/testsuite/ext/mt_allocator/22309_thread.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libstdc++-v3/testsuite/ext/mt_allocator/22309_thread.cc 
b/libstdc++-v3/testsuite/ext/mt_allocator/22309_thread.cc
index 2d94ea3a111..99cbb0ffbb8 100644
--- a/libstdc++-v3/testsuite/ext/mt_allocator/22309_thread.cc
+++ b/libstdc++-v3/testsuite/ext/mt_allocator/22309_thread.cc
@@ -22,6 +22,7 @@
 #include <pthread.h>
 #include <cstdlib>
 #include <stdexcept>
+#include <string>
 
 void
 check_dlopen(void*& h)
-- 
2.36.1