The IGV implicitly presents us with a list of the compile phases found in phasetype.hpp as they were executed. It would be helpful to have this list of phases printed to the commandline to be able to diff it with different executions.

I propose a diagnostic command line argument for C2 -XX:PrintPhaseLevel=n that prints the name of the compiler phase in print_method() with a level less or equal than n - analogous to how -XX:PrintIdealGraphLevel works.