[libc++] Fix backdeployment annotations for std::filesystem
In 1fa27f2a10e8, we made <filesystem>'s iterator types model concepts
from <ranges>, but we forgot to add the appropriate availability
annotations. This broke back-deployment to platforms that don't have
<filesystem> for which we have availability annotations.
For some reason, this wasn't caught by our back-deployment CI.
I believe this is due to the fact that we use a slightly older
compiler in the CI, and perhaps that compiler does not honour
our `#pragma clang attribute push` properly.
Differential Revision: https://reviews.llvm.org/D114456
NOKEYCHECK=True
GitOrigin-RevId: 7a0584fe3fd6b342d56251e92acc437961c8d29d
diff --git a/include/filesystem b/include/filesystem
index dcbdbba..6a42824 100644
--- a/include/filesystem
+++ b/include/filesystem
@@ -3024,13 +3024,17 @@
#if !defined(_LIBCPP_HAS_NO_RANGES)
template <>
+_LIBCPP_AVAILABILITY_FILESYSTEM
inline constexpr bool _VSTD::ranges::enable_borrowed_range<_VSTD_FS::directory_iterator> = true;
template <>
+_LIBCPP_AVAILABILITY_FILESYSTEM
inline constexpr bool _VSTD::ranges::enable_borrowed_range<_VSTD_FS::recursive_directory_iterator> = true;
template <>
+_LIBCPP_AVAILABILITY_FILESYSTEM
inline constexpr bool _VSTD::ranges::enable_view<_VSTD_FS::directory_iterator> = true;
template <>
+_LIBCPP_AVAILABILITY_FILESYSTEM
inline constexpr bool _VSTD::ranges::enable_view<_VSTD_FS::recursive_directory_iterator> = true;
#endif