[clang] [llvm] [RISCV] Add stack clash protection (PR #117612)

[Sam Elliott via llvm-commits]

lenary wrote:

> > @rzinsly do you need someone to commit this?
> 
> Yes, please.

Please turn off [Keep my email addresses private](https://github.com/settings/emails) setting in your account. Otherwise the commit will be from the github hidden email which we don't use in LLVM. 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/117612