This still seems to be happening after <http://trac.webkit.org/changeset/200632> https://build.webkit.org/builders/Apple%20El%20Capitan%20Debug%20JSC%20%28Tests%29/builds/2785 https://build.webkit.org/builders/Apple%20El%20Capitan%20Release%20JSC%20%28Tests%29/builds/5799 https://build.webkit.org/builders/Apple%20Yosemite%20Debug%20JSC%20%28Tests%29/builds/5844 https://build.webkit.org/builders/Apple%20Yosemite%20Release%20JSC%20%28Tests%29/builds/11044
Saam is already working on this.
That test discovered a latent bug in B3. I will have a patch ready in the morning.
*** This bug has been marked as a duplicate of bug 157548 ***