Imports of package operand

PathSynopsis
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
github.com/mmcloughlin/avo/regPackage reg provides types for physical and virtual registers, and definitions of x86-64 register families.
strconvPackage strconv implements conversions to and from string representations of basic data types.
stringsPackage strings implements simple functions to manipulate UTF-8 encoded strings.