D6597: rust-2018: switch hg-core and hg-cpython to rust 2018 edition

[durin42 (Augie Fackler)]

durin42 added a comment.


  LGTM, but needs rebased (sorry for slow response)

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D6597/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D6597

To: Alphare, #hg-reviewers, kevincox
Cc: pulkit, durin42, kevincox, mercurial-devel