GNUmifluz: SH_CIRCLEQ_REMOVE

do { \
 if (SH_CIRCLEQ_NEXTP(elm, field, type) == (void *)(head)) \
 (head)->scqh_last += (elm)->field.scqe_prev; \
 else \
 SH_CIRCLEQ_NEXTP(elm, field, type)->field.scqe_prev += \
 (elm)->field.scqe_prev; \
 if (SH_CIRCLEQ_PREVP(elm, field, type) == (void *)(head)) \
 (head)->scqh_first += (elm)->field.scqe_next; \
 else \
 SH_CIRCLEQ_PREVP(elm, field, type)->field.scqe_next += \
 (elm)->field.scqe_next; \
} while (0)