llvm dev - Jul 2021 - release/13.x branch has been created

Hi,

I've created release/13.x branch.  We will wait a few days to make sure
the branch is stable and then 13.0.0-rc1 will be released on Friday.

If you have patches you want to backport to the release/13.x branch
you can email me or file a bug that blocks the release-13.0.0 metabug[1].

In addition to bug fixes, small features or patches that complete some
larger features may be accepted, just ask before pushing to the branch.

-Tom

[1] https://bugs.llvm.org/show_bug.cgi?id=release-13.0.0