tests/test-check-commit.t

rust-re2: add wrapper for calling Re2 from Rust

This assumes that Re2 is installed following Google's guide. I am not sure
how we want to integrate it in the project, but I think a follow-up patch would
be more appropriate for such work.
As it stands, *not* having Re2 installed results in a compilation error, which
is a problem as it breaks install compatibility. Hence, this is gated behind
a non-default `with-re2` compilation feature.

Differential Revision: https://phab.mercurial-scm.org/D7910

#require test-repo

Enable obsolescence to avoid the warning issue when obsmarker are found

  $ . "$TESTDIR/helpers-testrepo.sh"

Go back in the hg repo

  $ cd $TESTDIR/..

  $ REVSET='not public() and ::. and not desc("# no-check-commit")'

  $ mkdir "$TESTTMP/p"
  $ REVS=`testrepohg log -r "$REVSET" -T.`
  $ if [ -n "$REVS" ] ; then
  >   testrepohg export --git -o "$TESTTMP/p/%n-%h" -r "$REVSET"
  >   for f in `ls "$TESTTMP/p"`; do
  >      contrib/check-commit < "$TESTTMP/p/$f" > "$TESTTMP/check-commit.out"
  >      if [ $? -ne 0 ]; then
  >          node="${f##*-}"
  >          echo "Revision $node does not comply with rules"
  >          echo '------------------------------------------------------'
  >          cat ${TESTTMP}/check-commit.out
  >          echo
  >     fi
  >   done
  > fi