Registers native methods with the class specified by the clazz argument

Property definitions

jvm $ JniEnv :: register_natives
	# Registers native methods with the class specified by the `clazz` argument
	fun register_natives(clazz: JClass, method: JNINativeMethod, n_method : Int): Int `{
		return (*self)->RegisterNatives(self, clazz, method, n_method);
	`}
lib/jvm/jvm.nit:238,2--241,3