A way to align already compiled methods with compiler directives

Compiler Control (https://openjdk.org/jeps/165) provides method-context dependent control of the JVM compilers (C1 and C2).

If directives are added or changed, but compilation does not start, then the state of compiled methods doesn't correspond to the rules. This is not an error, and it happens in long running applications when directives are added or removed after compilation of methods that could be matched. For example, the user decides that C2 compilation needs to be disabled for some method due to a compiler bug, issues such a directive but this does not affect the application behavior. In such case, the target application needs to be restarted, and such an operation can have high costs and risks.

It would be convenient to optionally reconcile at least existing matching nmethods to the current stack of compiler directives to avoid the restarts described above. Another goal is testing/debugging the JVM compilers.