With this commit we add a benchmarks project that contains the necessary build
infrastructure and an example benchmark. It is added as a separate project to avoid
interfering with the regular build too much (especially sanity checks) and to keep
the microbenchmarks isolated.
Microbenchmarks are generated with `gradle :benchmarks:jmhJar` and can be run with
` gradle :benchmarks:jmh`.
We intentionally do not use the
[jmh-gradle-plugin](https://github.com/melix/jmh-gradle-plugin) as it causes all
sorts of problems (dependencies are not properly excluded, not all JMH parameters
can be set) and it adds another abstraction layer that is not needed.
Closes#18242
Daniel Mitterdorfer