const fmt.octalDigits

4 uses

	fmt (current package)
		scan.go#L560: 	octalDigits       = "01234567"
		scan.go#L579: 		digits = octalDigits
		scan.go#L627: 		return 0, octalDigits + "_", true
		scan.go#L632: 		return 0, octalDigits + "_", true