[libc++] Add basic support for -std=c++2b.
* Add feature test macros.
* Add buildbot configuration generic-cxx2b that uses clang-tot.
Reviewed By: ldionne, #libc
Differential Revision: https://reviews.llvm.org/D94227
GitOrigin-RevId: 95729f95d803c8e8f4ca3e6767404ec2c0492d53
diff --git a/docs/TestingLibcxx.rst b/docs/TestingLibcxx.rst
index 12edc23..04930e1 100644
--- a/docs/TestingLibcxx.rst
+++ b/docs/TestingLibcxx.rst
@@ -120,7 +120,7 @@
.. option:: std=<standard version>
- **Values**: c++03, c++11, c++14, c++17, c++2a
+ **Values**: c++03, c++11, c++14, c++17, c++2a, c++2b
Change the standard version used when building the tests.