This change happened due to post-commit feedback on the review.
an error to a warning under the ``-Wreserved-module-identifier`` warning
group. This warning is enabled by default. This addresses `#61446
<https://github.com/llvm/llvm-project/issues/61446>`_ and allows easier
- building of precompiled modules. This diagnostic may be strengthened into an
+ building of standard modules. This diagnostic may be strengthened into an
error again in the future once there is a less fragile way to mark a module
as being part of the implementation rather than a user module.