Generalize `setup_oss_toolchain.sh` a bit (#505)
Generalize `setup_oss_toolchain.sh` a bit (#505)

Summary:
Pull Request resolved: https://github.com/facebook/redex/pull/505

Make it generic to Ubuntu/Debian, at least.

Reviewed By: amnn

Differential Revision: D22635920

fbshipit-source-id: 996acf3ea8d9b1d4bd783164e3c0b66f170600ed

facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex