507f697860
If a function is fully optimized away in pre-link, it won't show up in `SymbolMap` in post-link and the check of unused profile would treat it as unused and allow it to be matched with unrelated functions. Extend the check to cover such case in post link. Also make `FuncToProfileNameMap` a MapVector so that we always get the same iterator sequence out of it in `UpdateWithSalvagedProfiles`.