[clang] [clang] Introduce "binary" StringLiteral for #embed data (PR #127629)

[Aaron Ballman via cfe-commits]

AaronBallman wrote:

> > No changelog because we want to backport?
> 
> No changelog because I forgot. Should we backport though?

This seems simple enough to warrant backporting.

https://github.com/llvm/llvm-project/pull/127629