The verifier issues warnings when the set of files in .hg/store
doesn't align with the set of files that are advertised via
repo.file(f).files() for all files seen in ctx.files() changelog
This logic is reasonable for a default implementation. But some
stores may have extra files whose presence is harmless. Or those
stores may not have the same transaction rollback semantics that
unlink files as other stores.
This commit adds support for disabling the warning for orphaned
The simple store extension has been taught to set this flag.