_STD -> _VSTD to avoid macro clash on windows

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@134190 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/thread b/include/thread
index a04572f..ce3ca49 100644
--- a/include/thread
+++ b/include/thread
@@ -284,7 +284,7 @@
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 
     _LIBCPP_INLINE_VISIBILITY
-    void swap(thread& __t) {_STD::swap(__t_, __t.__t_);}
+    void swap(thread& __t) {_VSTD::swap(__t_, __t.__t_);}
 
     _LIBCPP_INLINE_VISIBILITY
     bool joinable() const {return __t_ != 0;}
@@ -325,7 +325,7 @@
 void
 __threaad_execute(tuple<_F, _Args...>& __t, __tuple_indices<_Indices...>)
 {
-    __invoke(_STD::move(_STD::get<0>(__t)), _STD::move(_STD::get<_Indices>(__t))...);
+    __invoke(_VSTD::move(_VSTD::get<0>(__t)), _VSTD::move(_VSTD::get<_Indices>(__t))...);
 }
 
 template <class _F>
@@ -345,8 +345,8 @@
 thread::thread(_F&& __f, _Args&&... __args)
 {
     typedef tuple<typename decay<_F>::type, typename decay<_Args>::type...> _G;
-    _STD::unique_ptr<_G> __p(new _G(__decay_copy(_STD::forward<_F>(__f)),
-                                __decay_copy(_STD::forward<_Args>(__args))...));
+    _VSTD::unique_ptr<_G> __p(new _G(__decay_copy(_VSTD::forward<_F>(__f)),
+                                __decay_copy(_VSTD::forward<_Args>(__args))...));
     int __ec = pthread_create(&__t_, 0, &__thread_proxy<_G>, __p.get());
     if (__ec == 0)
         __p.release();