Use shorter identifier for ConcatenatedModules
Use shorter identifier for ConcatenatedModules

See https://github.com/webpack/webpack/issues/5992#issuecomment-346384896 for rationale.

Fixes #5992

EliteScientist/webpack,SimenB/webpack,webpack/webpack,SimenB/webpack,NekR/webpack,webpack/webpack,NekR/webpack,webpack/webpack,SimenB/webpack,webpack/webpack,EliteScientist/webpack,SimenB/webpack