JDK 13: What Is AggressiveOpts?

The Java VM flag -XX:+AggressiveOpts was deprecated in JDK 11 [see JDK-8199777 and JDK-8199778] "because its behavior is ill-defined." The "Problem" section of JDK-8199778 further explains (I added the emphasis):

AggressiveOpts has been used as a catch-all method of enabling various experimental performance features, mostly targeted to improve score on very specific benchmarks. Most things it affected have been removed or integrated over time, leaving the behavior of the flag ill-defined and prone to cause more issues than it'll solve. The only effect that the flag currently has is setting AutoBoxCacheMax = 20000 and BiasedLockingStartupDelay = 500. Both can be done manually by setting the corresponding flags on the command line.

According to the document "Java HotSpot VM Options," the -XX:+AggressiveOpts flag was added with J2SE 5 Update 6 to "turn on point performance compiler optimizations that are expected to be default in upcoming releases."