tests/test-issue1089.t

fuzz: clean up some repetition on building parsers.so fuzzers

There was a lot of repetition here that I realized could be cleared out. I
think there's some more work we could do here, but this is enough for now.

Differential Revision: https://phab.mercurial-scm.org/D7568

https://bz.mercurial-scm.org/1089

  $ hg init
  $ mkdir a
  $ echo a > a/b
  $ hg ci -Am m
  adding a/b

  $ hg rm a
  removing a/b
  $ hg ci -m m a

  $ mkdir a b
  $ echo a > a/b
  $ hg ci -Am m
  adding a/b

  $ hg rm a
  removing a/b
  $ cd b

Relative delete:

  $ hg ci -m m ../a

  $ cd ..