Bug#836533: Firefox crashes in js::jit::SnapshotIterator::numAllocations(). Possibly GCC 6-related?

[Torbjörn Andersson]

Downgrading to Firefox 48.0-1 seems to fix the crash. This version was 
built with GCC 5.4.0, according to about:buildconfig. 48.0-1+b1 was 
built with 6.2.0.

Torbjörn Andersson