Comment 9 for bug 1258057

cherry-picked all commits from stable but not in release on top of release. Crash stops happening from commit 5105d5ceb85aab4f1b24fefcb39e525f5cdc8300 (Speedup JS instanceof operator) onwards. But cherry-picking that commit alone on top of v5.2.0 (release) doesn't solve it. Thus it's not such a straigh-forward pick.

It seems that V4 is under frank development from the number of commits changing its code in the "stable vs. release" diff. Which makes me wonder if it makes sense to cherry-pick stuff onto v5.2.0 as opposed to simply waiting for that code to really stabilize (i.e.. trying the latest stable)