Hello,
We are doing a private beta run of shadow (https://github.com/CENSUS/shadow) for Android's (6 & 7) libc jemalloc-based heap. A (semi) hidden feature of the upcoming release is that it also supports Firefox x86-64
If someone here is doing Android userland reversing and/or exploitation, I would be happy to provide a tarball.
No obligations of course, except keeping it private until the public release we plan to do at Infiltrate 2017. All comments/patches/suggestions would be appreciated!
Let me know.