tests/test-empty-dir.t

tests: conditionalize tests for various repo features

Working my down the long tail of test failures due to the simple
store.

We're now down to 38 failures with the simple store.

Differential Revision: https://phab.mercurial-scm.org/D3096

  $ hg init

  $ echo 123 > a
  $ hg add a
  $ hg commit -m "first" a

  $ mkdir sub
  $ echo 321 > sub/b
  $ hg add sub/b
  $ hg commit -m "second" sub/b

  $ cat sub/b
  321

  $ hg co 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ cat sub/b 2>/dev/null || echo "sub/b not present"
  sub/b not present

  $ test -d sub || echo "sub not present"
  sub not present