[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/FeatureTestMacroTable.rst b/docs/FeatureTestMacroTable.rst
index 4815077..020ef2a 100644
--- a/docs/FeatureTestMacroTable.rst
+++ b/docs/FeatureTestMacroTable.rst
@@ -84,7 +84,7 @@
------------------------------------------------- -----------------
``__cpp_lib_bool_constant`` ``201505L``
------------------------------------------------- -----------------
- ``__cpp_lib_boyer_moore_searcher`` *unimplemented*
+ ``__cpp_lib_boyer_moore_searcher`` ``201603L``
------------------------------------------------- -----------------
``__cpp_lib_byte`` ``201603L``
------------------------------------------------- -----------------