var runtime.cleanupFnPtrMask

2 uses

	runtime (current package)
		mcleanup.go#L295: var cleanupFnPtrMask = [...]uint8{0b111}
		mgcmark.go#L492: 	scanblock(uintptr(unsafe.Pointer(&spc.cleanup)), unsafe.Sizeof(cleanupFn{}), &cleanupFnPtrMask[0], gcw, nil)