D7910: rust-re2: add wrapper for calling Re2 from Rust

[kevincox (Kevin Cox)]

kevincox added a comment.


  While I think the rust regex crate is heavily inspired by RE2 and uses a fairly compatible syntax I don't think there is a goal to be 100% compatible and I would be surprised if there weren't any differences. What I am trying to say is that if we are going to change engines we may as well change to `regex`. If we are using `RE2` for backwards compatibility then this change makes sense.

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D7910/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D7910

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