[llvm] [BOLT][NFC] Unify two symbol table iterations (PR #90724)

[Amir Ayupov via llvm-commits]

aaupov wrote:

> Hmm, my system clang-18 and pre-built clang binary from llvm-release page is not able to be processed because of the compile option (in my guess)
> 
> ```
> BOLT-ERROR: instrumentation runtime libraries require relocation
> ```

Sorry, yes, instrumentation requires relocations in the input binary. I've checked that rewriting in `-lite=0` mode works:
```
llvm-bolt clang-18 -lite=0 -o /dev/null
```

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