And same for -m<module> - becuase Python supports it this way.

Before the patch:

	$ python '-cprint "hello world"'
	hello world
	$ gpython '-cprint "hello world"'
	unknown option: '-cprint "hello world"'

After the patch:

	$ python '-cprint "hello world"'
	hello world
	$ gpython '-cprint "hello world"'
	hello world

/reviewed-on nexedi/pygolang!5