Sukhbir Singh authored Jun 12, 2018 and Georg Koppen committed Jun 14, 2018

Also enable rust for all builds.

The main change is the removal of the --enable-jemalloc=4 option which
was done with #22482.

Update the mozconfig files with the changes from the versions in
tor-browser.git. We are currently not using the mozconfig files from
tor-browser.git directly as we need to modify some of them.