The experimental support for Compiler Blackholes is added. These are useful for low-level benchmarking, to avoid dead-code elimination on the critical paths, without affecting the benchmark performance. Current support is implemented as CompileCommand, accessible as `-XX:CompileCommand=blackhole,<method>`, with the plan to eventually graduate it to a public API.

JMH is already able to auto-detect and use this facility when instructed/available. Please consult JMH documentation for the next steps.