k := base + i*words + j
				out[k/8] |= 1 << (k % 8)
			}
		}
	}
}

// appendGCProg appends the GC program for the first ptrdata bytes of
// typ to dst and returns the extended slice.
func appendGCProg(dst []byte, typ *abi.Type) []byte {
	if typ.Kind_&abi.KindGCProg != 0 {
		// Element has GC program; emit one element.
		n := uintptr(*(*uint32)(unsafe.Pointer(typ.GCData)))