Constant CALL_LEAF 

pub const CALL_LEAF: u8 = 0x7E;

Frameless call to a leaf+thin+args-only function. No CallFrame is pushed — just saves (fn_id, ip) in the dispatch loop, sets bp to the args already on stack, and jumps to the target. On RETURN, restores the caller’s state directly. Format: fn_id:u16, argc:u8 (same as CALL_KNOWN).