[clang] Ofast deprecation clarifications (PR #101005)

[Sjoerd Meijer via cfe-commits]

sjoerdmeijer wrote:

> LGTM, let's go ahead and merge this and get it backported to 19.x, thank you!

Thanks for your help with this.

I am mostly unfamiliar with the release process. Do you know how we can achieve this? Do we suggest this commit to the release manager for a backport and cherry pick? Or do we prepare a patch?

We could add similar clarifications to the release notes, which were initially included in an earlier version of this patch. So same question how we would need to approach that.

https://github.com/llvm/llvm-project/pull/101005