Write an optimizer FAQ

[retronym]

Random points (need cleanup)

• What optimizations are implemented? What do they do?
• Why should I use the optimizer (isn't the JVMs good enough)?
• What options should I use?
• What happens to binary compatibility?
• When can I inline from the classpath?
• What are the limitations?

[lrytz]

started in https://github.com/scala-opt/scala/wiki/Scala-2.12-Bytecode-Optimizer

[SethTisue]

retargeted for 2.12.x