Cabal revisions of dlist-0.6

Hackage metadata revisions edit the .cabal file after upload; each diff below is one revision.

 name:                   dlist version:                0.6+x-revision: 1 synopsis:               Difference lists description:   Difference lists are a list-like type supporting O(1) append. This is   location:             git://github.com/spl/dlist.git  library+  -- Semigroup is superclass of Monoid+  build-depends: base <4.11+   build-depends:        base >= 2 && < 5   ghc-options:          -Wall   extensions:           CPP