[llvm] [IPO] NFC: avoid recalculating FunctionId hashes during ProfiledCallGraph construction (PR #109014)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

The idea here looks reasonable to me, but I'm not familiar with this code. (I see that FunctionId itself can also store a hash, so I'm a bit unsure if the solution here should be something else.)

https://github.com/llvm/llvm-project/pull/109014