[libcxx-commits] [libcxx] [libc++][doc] Update the release notes for LLVM 19. (PR #99061)

[Mark de Wever via libcxx-commits]

================
@@ -59,6 +59,16 @@ Deprecations and Removals
 Upcoming Deprecations and Removals
 ----------------------------------
 
+LLVM 20
+~~~~~~~
+
+- The ``LIBCXX_ENABLE_ASSERTIONS`` CMake variable and the ``_LIBCPP_ENABLE_ASSERTIONS`` macro that were used to enable
+  the safe mode will be removed in LLVM 20.
+
+- The C++20 synchronization library will be removed entirely in language modes prior to C++20 in LLVM 20.
+
+- The ``_LIBCPP_ENABLE_REMOVED_ALLOCATOR_CONST`` macro will no longer have an effect.
----------------
mordante wrote:

Fix that. I've also copy-pasted the C++03 removal to this file.

https://github.com/llvm/llvm-project/pull/99061