From some initial investigate into the build process for Firefox, it looks like one of the only things that is blocking us from adopting bitcode-enabled builds is the libcrypto.a and libssl.a dependencies FxA requires. This forces all of the targets that depend on FxA to also have bitcode turned off because the bitcode-yness of the all dependencies must match. We'll need to investigate ways we can produce a bitcode-enabled FxA build.
This blocks having useful crash reports.
Stefa has a patch in the works to remove openssl.