[llvm] TableGen: Sort RuntimeLibcallImpls secondarily by enum names (PR #150728)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> ### Merge activity
> * **Jul 26, 1:44 AM UTC**: [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/150728) rebased this pull request as part of a merge.

I think all the checks passed, and then it started the whole process over? Is it trying to redo tests if anything else already merged to main?

https://github.com/llvm/llvm-project/pull/150728