This fixes a corner case where the generator function of a suspended
generator has been marked for optimization. We assume the optimization
approach will cause a bailout because generators are not optimized. But
resuming is more resilient by always activating the unoptimized code.

R=neis@chromium.org,bmeurer@chromium.org
TEST=mjsunit/regress/regress-crbug-513471
BUG=chromium:513471
LOG=n

Review URL: https://codereview.chromium.org/1856683002

Cr-Commit-Position: refs/heads/master@{#35234}