[llvm] [Thumb1] LivePhysRegs to LiveRegUnits (PR #84474)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

Email address is still hidden.  Quoting the automated message that's supposed to trigger (not sure why it didn't trigger here):

> ⚠️ We detected that you are using a GitHub private e-mail address to contribute to the repo. Please turn off [Keep my email addresses private](https://github.com/settings/emails) setting in your account. See [LLVM Discourse](https://discourse.llvm.org/t/hidden-emails-on-github-should-we-do-something-about-it) for more information.

https://github.com/llvm/llvm-project/pull/84474