tests: output_spec: use shell-test REP_NODELAY (#10726)

Fix flaky "shell command :! throttles shell-command output greater than ~10KB:":

    [ RUN      ] shell command :! throttles shell-command output greater than ~10KB:
    warning: Screen changes were received after the expected state. This indicates
    indeterminism in the test. Try adding screen:expect(...) (or wait()) between
    asynchronous (feed(), nvim_input()) and synchronous API calls.
      - Use screen:redraw_debug() to investigate; it may find relevant intermediate
        states that should be added to the test to make it more robust.
      - If the purpose of the test is to assert state after some user input sent
        with feed(), adding screen:expect() before the feed() will help to ensure
        the input is sent when Nvim is in a predictable state. This is preferable
        to wait(), for being closer to real user interaction.
      - wait() can trigger redraws and consequently generate more indeterminism.
        Try removing wait().

    ERR
    test/functional/ui/screen.lua:579: Failed to match any screen lines.
    Expected (anywhere): "
    %."
    Actual:
      |XXXXXXXXXX 591                                    |
      |XXXXXXXXXX 592                                    |
      |XXXXXXXXXX 593                                    |
      |XXXXXXXXXX 594                                    |
      |                                                  |
      |                                                  |
      |{3:-- TERMINAL --}                                    |
    stack traceback:
            test/functional/ui/screen.lua:579: in function '_wait'
            test/functional/ui/screen.lua:367: in function 'expect'
            test/functional/ui/output_spec.lua:63: in function <test/functional/ui/output_spec.lua:53>

Log: https://travis-ci.org/neovim/neovim/jobs/569082705#L5355
(gcc-functionaltest-lua)

0 files changed, 0 insertions, 0 deletions