KOS_OP_TAIL_CALL_ATTR

• Style: EXTRA. Schema: CONST (attr name), COUNT (npos), NOARG, NOARG. One cache slot (attr resolution).

• Stack: Same layout as CALL_ATTR: [..., obj, arg_0, ..., arg_{N-1}]. obj.name resolves as CALL_ATTR describes, then the call is made in tail position: a Koskari function takes over the caller’s frame rather than a new frame being pushed, and any other callable is called as TAIL_CALL describes.

• Compiler form: Produced by the processor’s promote_tail_calls pass relabeling a tail-position CALL_ATTR in function-body code; never emitted by a special.