When nmethod is registered (method->_code is set) it calls nmethod::post_compiled_method_load_event() which trigger DTrace and JVMTI event.
We should do the same for AOT compiled methods. Otherwise agents which use JVMTI will not known about AOT methods and it may cause problem for calls stack parsing (for example, inlining info will be missing).

And call post_compiled_method_unload() when AOT method made non entrant.