We hardcoded this accidentally in the original CL for the turbofan case,
instead we need to call JSConstructStubGeneric() which will return the
correct construct stub based on the harmony_restrict_constructor_return
flag.

Bug: chromium:829899
Change-Id: I6776a5daebd57d8881d926ad68595141312a877d
Reviewed-on: https://chromium-review.googlesource.com/1001893Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52470}