[compiler-rt] [compiler-rt][rtsan] intercept setbuf, setvbuf, setlinebuf and setbuffer (PR #121616)

[Chris Apple via llvm-commits]

cjappl wrote:

@devnexen - I'd love to keep being added to these reviews alongside @davidtrevelyan :)

Thank you!!

https://github.com/llvm/llvm-project/pull/121616