[libc++] Implement C++20's P0784 (More constexpr containers)
This commit adds std::construct_at, and marks various members of
std::allocator_traits and std::allocator as constexpr. It also adds
tests and turns the existing tests into hybrid constexpr/runtime tests.
Thanks to Richard Smith for initial work on this, and to Michael Park
for D69803, D69132 and D69134, which are superseded by this patch.
Differential Revision: https://reviews.llvm.org/D68364
Cr-Mirrored-From: https://chromium.googlesource.com/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 0724f8bf47f8cb073d41e2750d45d5b05e66bf0b
diff --git a/docs/FeatureTestMacroTable.rst b/docs/FeatureTestMacroTable.rst
index 66162d7..0f17a3a 100644
--- a/docs/FeatureTestMacroTable.rst
+++ b/docs/FeatureTestMacroTable.rst
@@ -192,6 +192,8 @@
------------------------------------------------- -----------------
``__cpp_lib_concepts`` *unimplemented*
------------------------------------------------- -----------------
+ ``__cpp_lib_constexpr_dynamic_alloc`` ``201907L``
+ ------------------------------------------------- -----------------
``__cpp_lib_constexpr_misc`` *unimplemented*
------------------------------------------------- -----------------
``__cpp_lib_constexpr_swap_algorithms`` *unimplemented*