Enable argv support for horizon OS

[ian-h-chamberlain]

With 3dslink and the hbmenu there is builtin support for passing argv directly to a 3dsx binary. This enables reading them instead of the stub implementation used by espidf.

Example, with this patch and latest version of 3dslink and hbmenu:

//...
println!("{:?}", std::env::args().collect::<Vec<_>>());
//...

3dslink target/armv6k-nintendo-3ds/debug/examples/hello-world.3dsx -0 hello-world -- --x -y z

@Meziu @AzureMarker

[AzureMarker]

Oh nice, this also works towards enabling stack overflow protection in main (the stackoverflow imp module is still a no-op).