Nico Rieck:  this patch series fixes visibility issues on Windows as explained in <http://lists.cs.uiuc.edu/pipermail/cfe-dev/2013-August/031214.html>.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@188192 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/__mutex_base b/include/__mutex_base
index 0583df9..a73e400 100644
--- a/include/__mutex_base
+++ b/include/__mutex_base
@@ -77,7 +77,7 @@
 #endif
 
 template <class _Mutex>
-class _LIBCPP_TYPE_VIS lock_guard
+class _LIBCPP_TYPE_VIS_ONLY lock_guard
 {
 public:
     typedef _Mutex mutex_type;
@@ -101,7 +101,7 @@
 };
 
 template <class _Mutex>
-class _LIBCPP_TYPE_VIS unique_lock
+class _LIBCPP_TYPE_VIS_ONLY unique_lock
 {
 public:
     typedef _Mutex mutex_type;