[clang] [Clang][attr] Add 'cfi_salt' attribute (PR #141846)

[Bill Wendling via cfe-commits]

bwendling wrote:

> > You need to realize that submitted this code for review in May. It's like that I forgot some of the details of why I wrote something. But what I wrote was intentionally put there for a reason.
> > There's a new commit. PTAL.
> 
> Honestly, this is a case where I was heavily unmotivated to review your code due to past behavior, and didn't until asked explicitly by Aaron. It waited due to your inability to respect reviewers in the past.

I'm sorry for my behavior. I don't intend to be confrontational, but people keep arguing with me about code that I've written intentionally to avoid ICEs and the like. But when you wrote this:

> EITHER:
> 1- You're not assuming anything, thus this check should diagnose incorrect argument count.
> 2- This is a 'dead' branch, and should just be an assume.

I found it insulting and lost my temper, because I understood what you're said before this. I shouldn't have, but really I know why you want asserts there. I didn't make it an assert because it would ICE otherwise.

https://github.com/llvm/llvm-project/pull/141846