Function dispatch_excall 

pub fn dispatch_excall(
    ctx: &mut CommandContext,
    op: i32,
    params: &[Value],
) -> Result<bool>

Dispatch the SCRIPT child of EXCALL.

Siglus 1.1.137 routes EXCALL.SCRIPT to a distinct handler rather than to the normal SCRIPT handler: only the font overrides live in C_elm_excall. Newer 1.1.141.2 scene bytecode also reaches the recovered joypad override commands through EXCALL.SCRIPT while preparing configured system scenes.