This fixes a corner-case where resuming a suspended generator would not
perform stack overflow checks and hence cause the stack to grow without
bounds.

R=neis@chromium.org
BUG=chromium:781583

Change-Id: Ib04116e489ac6b962cb821263860497abb57bbae
Reviewed-on: https://chromium-review.googlesource.com/765953Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49327}