libstdc++: Ensure std::lock_guard is declared

libstdc++-v3/ChangeLog:

	* include/std/syncstream: Include <bits/std_mutex.h>
	unconditionally.

diff --git a/libstdc++-v3/include/std/syncstream b/libstdc++-v3/include/std/syncstream
index 5e0864ec54a8eb9fcd3bedbff49067b993cb8754..9d1db0cf286e2724655aa1565051aa66833983d4 100644 (file)
--- a/libstdc++-v3/include/std/syncstream
+++ b/libstdc++-v3/include/std/syncstream
@@ -44,10 +44,7 @@
 #include <bits/allocator.h>
 #include <bits/functexcept.h>
 #include <bits/functional_hash.h>
-
-#if _GLIBCXX_HAS_GTHREADS
-# include <bits/std_mutex.h>
-#endif
+#include <bits/std_mutex.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {