[clang] [llvm] [MC,llvm-readobj,yaml2obj] Support CREL relocation format (PR #91280)

[James Henderson via llvm-commits]

jh7370 wrote:

> [jh7370](https://github.com/jh7370) sorry for pinging again. I will be highly grateful if you kindly review this pull request. This change will unblock some of our internal tasks and timely completion of this is crucial for us. Thank you in advance.

I hope to look at this in the next day or two - I've had my head down in some local work, so have avoided more complex reviews the past week.

https://github.com/llvm/llvm-project/pull/91280