[llvm] [Draft][BOLT] fix hugify for old kernels (#201813) (PR #201818)

[Paschalis Mpeis via llvm-commits]

https://github.com/paschalis-mpeis commented:

> We can parse proc_pid_maps for the actual mapping if necessary.

Parsing proc maps is a bit hacky, no?

https://github.com/llvm/llvm-project/pull/201818