Dimitry Andric:  many visibility fixes.  Howard:  Much appreciated.  Can you send me a patch to CREDITS.TXT?

llvm-svn: 163862
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: aeb85680fb688e96ba2d2fc7703ae6e57cc44097
diff --git a/include/mutex b/include/mutex
index 61f53e0..ee20f02 100644
--- a/include/mutex
+++ b/include/mutex
@@ -425,17 +425,19 @@
 
 #endif  // _LIBCPP_HAS_NO_VARIADICS
 
-struct once_flag;
+struct _LIBCPP_VISIBLE once_flag;
 
 #ifndef _LIBCPP_HAS_NO_VARIADICS
 
 template<class _Callable, class... _Args>
-  void call_once(once_flag&, _Callable&&, _Args&&...);
+_LIBCPP_INLINE_VISIBILITY
+void call_once(once_flag&, _Callable&&, _Args&&...);
 
 #else  // _LIBCPP_HAS_NO_VARIADICS
 
 template<class _Callable>
-  void call_once(once_flag&, _Callable);
+_LIBCPP_INLINE_VISIBILITY
+void call_once(once_flag&, _Callable);
 
 #endif  // _LIBCPP_HAS_NO_VARIADICS