Comment 0 for bug 1571017

[Impact]
libmozjs24 does not support 48-bit virtual addresses on arm64. 48-bit virtual addresses are enabled in the Ubuntu 16.04 kernel (though not on the kernel used on the buildds). This causes applications to crash.

[Test Case]
apt source mozjs24
sudo apt build-dep -y mozjs24
sudo apt install -y fakeroot
cd mozjs24-24.2.0
fakeroot make -f debian/rules build
cd js/src
make
./jsapi-tests/jsapi-tests

Unpatched source crashes for me immediately on xenial:
dannf@mustang:~/mozjs24-24.2.0/js/src$ ./jsapi-tests/jsapi-tests
testXDR_sourceMap
Segmentation fault

All tests pass w/ patched source

[Regression Risk]
I'd suggest running through the jsapi-tests on each supported Ubuntu architecture. I've only ran it on arm64 so far.