[llvm] [BOLT][NFC] Added double escape characters (PR #93348)

[Alexander Yermolovich via llvm-commits]

ayermolo wrote:

> (personally - I'm not sure if this convention is really a great one, especially unsure whether it's worthwhile mass-migrating code to use it... (seems like it's pretty close to other broad formatting changes which we don't usually apply broadly) - before any of these patches go in, maybe worth a discourse thread?)

@sayhaan  is my intern and I asked him to do it as a startup task primarily to get familiar with the PR workflow (thus only BOLT tests). :)
Personally I don't have a strong opinion about it, but figure might as well since it seems like a current convention.

https://github.com/llvm/llvm-project/pull/93348