Reland [libc++] [P0325] Implement to_array from LFTS with updates.

Fixed expected errors and notes.

Summary:
This patch implements https://wg21.link/P0325.

Reviewers: EricWF, mclow.lists, ldionne, lichray

Reviewed By: ldionne, lichray

Subscribers: lichray, dexonsmith, zoecarver, christof, ldionne, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D69882

Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: e93e58c6c40a365bc9275dd8a8242598343cc835
diff --git a/include/version b/include/version
index 2abc71e..2d9a2b3 100644
--- a/include/version
+++ b/include/version
@@ -101,6 +101,7 @@
 __cpp_lib_string_udls                                   201304L <string>
 __cpp_lib_string_view                                   201606L <string> <string_view>
 __cpp_lib_three_way_comparison                          201711L <compare>
+__cpp_lib_to_array                                      201907L <array>
 __cpp_lib_to_chars                                      201611L <utility>
 __cpp_lib_transformation_trait_aliases                  201304L <type_traits>
 __cpp_lib_transparent_operators                         201510L <functional>
@@ -233,6 +234,7 @@
 # endif
 // # define __cpp_lib_list_remove_return_type              201806L
 // # define __cpp_lib_ranges                               201811L
+# define __cpp_lib_to_array                                201907L
 // # define __cpp_lib_three_way_comparison                 201711L
 #endif