Registers new OPT instruction or a group of instructions. The $obj may be either a name of the class that extends optInstruction class, or an array of such names. Note the instructions you are going to register, have to be already loaded to the application, because this metod must execute some of their methods to get their syntax info, if the compiler is used. In order to avoid this, call optClass::registerInstructionFile() first.

Note: this method is not available, if the Register method family was removed from the source with OPT Configurator.