In Leyden, we have the extended compilation timings printouts with -XX:+PrintCompilation / UL, that are very useful to study compiler dynamics. These timings include:
 - time the task spent before queuing, shows the queue bottlenecks
 - time the task spent in the queue, shows compiler load delays
 - time the task spent actually compiling, shows the per-method compilation costs

We should consider the same kind of printout for mainline.

This would also require us to print the compilation task _after_ the compilation, not only before it.

This improvement would also obviate any need for PrintCompilation2 flag, JDK-8356028.