R8 is a whole-program optimizer that converts Java byte code to
optimized dex code. It can be run with the same general steps (and JAR)
as the existing D8 compiler.
This change adds R8Compiler and the R8 keep-annotation library it relies
on, makes this lib + Android API stubs default libraries for Android
Java/Kotlin, and includes a small update to allow older versions of
dex2oat (33.10) to run.
https://r8.googlesource.com/r8
