brson 21
Updating with:
- fix emscripten unwinding and unimplemented symbols
- investigate emscripten patch without fastcomp https://github.com/rust-lang/rust/issues/36356
- organize bors-next effort
- https://github.com/rust-community/bors
- https://github.com/rust-community/team/issues/58
- https://github.com/AelitaBot/aelita
- http://github.com/servo/homu
- @ locks, @ booya, @ notriddle, @ aLi, @ frewsxcv, @ Manishearth
- follow up on bitcode issue https://github.com/rust-lang/rust/issues/35968
- write typescript / spidermonkey bindings for tokio