[libc++] Switch to the new testing configurations by default
We've been meaning to remove support for the legacy testing configuration
for a long time. This patch switches the default from the legacy config
to the appropriate new-style configuration based on a few hints.
We've been running with the new-style configuration for more than a year
in our CI, however it's possible that this will uncover issues with some
users that run the tests on platforms that we don't support yet with the
new-style configs. Unfortunately, there is no way to know about it other
than to land this patch and see whether anything breaks.
Differential Revision: https://reviews.llvm.org/D121632
NOKEYCHECK=True
GitOrigin-RevId: d0af4276d62418ba9e54fec99b293d2fd7c92213
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index ee1cc81..9e2e4a7 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -106,3 +106,9 @@
libc++abi already installs its headers in the right location. However, vendors building
libc++ against alternate ABI libraries should make sure that their ABI library installs
its own headers.
+
+- The legacy testing configuration is now deprecated and will be removed in the next release. For
+ most users, this should not have any impact. However, if you are testing libc++ in a configuration
+ or on a platform that used to be supported by the legacy testing configuration and isn't supported
+ by one of the configurations in ``libcxx/test/configs``, please reach out to the libc++ developers
+ to get your configuration supported officially.