Java Benchmarks: OpenJDK 8 Through OpenJDK 19 EA, OpenJ9, GraalVM CE

Stemming from a recent reader request around seeing some fresh OpenJDK performance benchmarks, here are benchmarks of OpenJDK 9 through OpenJDK 18 plus the early access OpenJDK 19 builds. Additionally, OpenJ9 and GraalVM CE were tossed in as alternative implementations.