Merge commit '2999b7307f70' from llvm.org/main into next

Author: git apple-llvm automerger

libcxx/include/__utility/decay_copy.h

@@ -21,9 +21,10 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY typename decay<_Tp>::type __decay_copy(_Tp&& __t)
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR
+typename decay<_Tp>::type __decay_copy(_Tp&& __t)
 #if _LIBCPP_STD_VER > 17
-    noexcept(is_nothrow_convertible_v<_Tp, remove_reference_t<_Tp> >)
+    noexcept(is_nothrow_convertible_v<_Tp, remove_reference_t<_Tp>>)
 #endif
 {
   return _VSTD::forward<_Tp>(__t);