[Hist][NFC] Convert a constant into a constexpr.
[Hist][NFC] Convert a constant into a constexpr.

olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root