Unqualified calls to std::move

[LorenDB]

https://github.com/bombela/backward-cpp/blob/647eccde8e87d7669be1be8c661e26f1a78a3244/backward.hpp#L1640-L1642

This causes a warning with Clang that unqualified calls to std::move are being performed. I haven't looked into the code much but it should probably be a matter of qualifying the calls with std:: (or a custom class/namespace if a custom move function is being used).

[davemoore22]

Yes, it is. At Line 414, there's a using std::move.