js.h wants to include machine/joystick.h for analog joystick support.
other platforms don't have such support, so hide it with an arch define.
this allows us to use the "portable game librarys" on more than one arch.
OK MANTAINER
PLIB is a suite of portable game librairies.
PLIB includes sound effects, music, a complete 3D engine, font
rendering, a simple Windowing library, a game scripting language, a GUI,
networking, 3D math library and a collection of handy utility functions.
All are 100% portable across nearly all modern computing platforms.
Each library component is fairly independent of the others - so if you
want to use SDL, GTK, GLUT, or FLTK instead of PLIB's 'PW' windowing
library, you can.
Based on a submission from Gallon Sylvestre (MAINTAINER)
