WASM mappings

During testing I noticed my controller (xbox 360) has a wrong mapping on WASM. The mapping is correct on native Linux. SDL_GameControllerDB doesn't seem to have a wasm section and the tools listed don't support wasm either.

So I'm guessing wasm is mapped through web-sys. I ran the following to see if Firefox identified my controller:

window.addEventListener("gamepadconnected", function(e) {
  console.log("Gamepad connected at index %d: %s. %d buttons, %d axes.",
  e.gamepad.index, e.gamepad.id,
  e.gamepad.buttons.length, e.gamepad.axes.length);
});

Response: Gamepad connected at index 0: 045e-028e-Microsoft X-Box 360 pad. 11 buttons, 8 axes.

So it seems to be recognized just fine. How do we fix the mapping?