[libc++] Implement std::boyer_moore{, _horspool}_searcher
This mostly copys the `<experimental/functional>` stuff and updates the code to current libc++ style.
Reviewed By: ldionne, #libc
Spies: nlopes, adamdebreceni, arichardson, libcxx-commits, mgorny
Differential Revision: https://reviews.llvm.org/D121074
NOKEYCHECK=True
GitOrigin-RevId: 971e9c80e9660285e0620682f4e470a41967391f
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index d2084ae..ba780d8 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -142,6 +142,10 @@
``_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS``, this ensures that the members of
``allocator<void>`` removed in C++20 can be accessed.
+- The experimental versions of ``boyer_moore_searcher`` and ``boyer_moore_horspool_searcher``
+ will be removed in LLVM 17. You can disable the deprecation warnings by defining
+ ``_LIBCPP_NO_EXPERIMENTAL_DEPRECATION_WARNING_SEARCHERS``.
+
ABI Changes
-----------