Crash in JSC::MarkedBlock::vm() const + 12 Seen with imported/w3c/canvas/2d.fillRect.clip.html https://build.webkit.org/results/Apple%20Yosemite%20Debug%20WK2%20(Tests)/r205740%20(14897)/results.html fast/layers/zindex-inherit.html https://build.webkit.org/results/Apple%20El%20Capitan%20Debug%20WK1%20(Tests)/r205729%20(8250)/results.html
*** This bug has been marked as a duplicate of bug 161796 ***