[llvm] [BOLT] Unify two symbol lookup interation into the one (PR #90724)

[Amir Ayupov via llvm-commits]

aaupov wrote:

Thanks Donghee! Looks good, but please retitle to "[BOLT][NFC] Unify two symbol table iterations".
One way to estimate the effect (in seconds) would be to exit(0) just above `auto CompareSymbols` and measure processing time before and after this fix. Can you please check with a large binary and add the information to the PR message?

https://github.com/llvm/llvm-project/pull/90724