Another attempt to fix regress-crbug-178790.

This time we simply undo the change introduced by the PPC port for
this test. No idea why it should be necessary, and Windows XP
obviously doesn't give us that much stack, anyway.

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/826833003

Cr-Commit-Position: refs/heads/master@{#26093}

test/mjsunit/regress/regress-crbug-178790.js

@@ -25,8 +25,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --stack-size=1800
-
 // Create a regexp in the form of a?a?...a? so that fully
 // traversing the entire graph would be prohibitively expensive.
 // This should not cause time out.