Summary says it.
Created attachment 150855 [details, diff] azureus ebuild diff
I've tried this for 4.0.0.2 and while it makes restarter work, azureus still thinks the plugin is not there and wants user to install it, so it's not very clean solution and who knows what happens if user upgrades to newer version than the one bundled inside?
OK so 4.0.0.2 installs upstream bundled plugins including restart support in shared plugin directory. Controlling debug compile flags however calls for more systematic solution.