[clang] [NFC][clang] Quote literal builtin attribute markers in Builtins.def docs (PR #160080)

[Radovan Božić via cfe-commits]

bozicrHT wrote:

> `{num}` seems clear enough yeah, though it should probably be defined somewhere in the file what we mean by ‘number’.
> 
> > I'm not sure it is a particularly good idea to have ONE be 2 characters, particularly with how it is parsed. I am afraid that above, all you did is test the thoroughness of our testing :)
> 
> Yeah, I agree.
> 
> > I can add something like this:
> 
> Yeah, something like that that seems fine
> 
> Other than that I stil think it’d make sense to move this to the internals manual, and if we’re really worried about people not finding this documentation if we move it, we can just leave a comment in the `.def` file along the lines of ‘the documentation here has been moved to [insert link here]’.

Thanks for the feedback! I’ve committed the changes as suggested. Please let me know if anything else needs adjustment.

https://github.com/llvm/llvm-project/pull/160080