[NFC] Rename _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS

The name _LIBCPP_TYPE_VIS_ONLY is no longer accurate because both
_LIBCPP_TYPE_VIS and _LIBCPP_TYPE_VIS_ONLY expand to
__attribute__((__type_visibility__)) with Clang. The only remaining difference
is that _LIBCPP_TYPE_VIS_ONLY can be applied to templates whereas
_LIBCPP_TYPE_VIS cannot (due to dllimport/dllexport not being allowed on
templates).

This patch renames _LIBCPP_TYPE_VIS_ONLY to _LIBCPP_TEMPLATE_VIS.

llvm-svn: 291035
diff --git a/libcxx/include/tuple b/libcxx/include/tuple
index 2f71cce..cddb709 100644
--- a/libcxx/include/tuple
+++ b/libcxx/include/tuple
@@ -471,7 +471,7 @@
 
 
 template <class ..._Tp>
-class _LIBCPP_TYPE_VIS_ONLY tuple
+class _LIBCPP_TEMPLATE_VIS tuple
 {
     typedef __tuple_impl<typename __make_tuple_indices<sizeof...(_Tp)>::type, _Tp...> base;
 
@@ -908,7 +908,7 @@
 };
 
 template <>
-class _LIBCPP_TYPE_VIS_ONLY tuple<>
+class _LIBCPP_TEMPLATE_VIS tuple<>
 {
 public:
     _LIBCPP_INLINE_VISIBILITY
@@ -1340,7 +1340,7 @@
 }
 
 template <class ..._Tp, class _Alloc>
-struct _LIBCPP_TYPE_VIS_ONLY uses_allocator<tuple<_Tp...>, _Alloc>
+struct _LIBCPP_TEMPLATE_VIS uses_allocator<tuple<_Tp...>, _Alloc>
     : true_type {};
 
 #endif // _LIBCPP_HAS_NO_VARIADICS