visibility-decoration.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@114496 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/fstream b/include/fstream
index e0259b9..e0c7dea 100644
--- a/include/fstream
+++ b/include/fstream
@@ -176,7 +176,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _CharT, class _Traits>
-class basic_filebuf
+class _LIBCPP_VISIBLE basic_filebuf
     : public basic_streambuf<_CharT, _Traits>
 {
 public:
@@ -957,7 +957,7 @@
 // basic_ifstream
 
 template <class _CharT, class _Traits>
-class basic_ifstream
+class _LIBCPP_VISIBLE basic_ifstream
     : public basic_istream<_CharT, _Traits>
 {
 public:
@@ -1102,7 +1102,7 @@
 // basic_ofstream
 
 template <class _CharT, class _Traits>
-class basic_ofstream
+class _LIBCPP_VISIBLE basic_ofstream
     : public basic_ostream<_CharT, _Traits>
 {
 public:
@@ -1247,7 +1247,7 @@
 // basic_fstream
 
 template <class _CharT, class _Traits>
-class basic_fstream
+class _LIBCPP_VISIBLE basic_fstream
     : public basic_iostream<_CharT, _Traits>
 {
 public: