checking build success of `-tags="ldbpost121"`

[Eric Theise]

Hi folks,

I've been away from imposm for a while and am rebuilding my executable on macOS.

Is it possible to determine from the executable if the optimizations mentioned in https://github.com/omniscale/imposm3 were triggered?

Do any macOS users have an opinion as to whether HyperLevelDB or LevelDB>1.21 yields better performance?

Thanks in advance; hope all of you are doing well.

Eric