internal/pkg: standardise artifact IR

This should hopefully provide good separation between the artifact curing backend implementation and the (still work in progress) language. Making the IR parseable also guarantees uniqueness of the representation.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/dir.go

@@ -28,14 +28,6 @@ type FlatEntry struct {
 |         data []byte          |
 */
 
-// wordSize is the boundary which binary segments are always aligned to.
-const wordSize = 8
-
-// alignSize returns the padded size for aligning sz.
-func alignSize(sz int) int {
-	return sz + (wordSize-(sz)%wordSize)%wordSize
-}
-
 // Encode encodes the entry for transmission or hashing.
 func (ent *FlatEntry) Encode(w io.Writer) (n int, err error) {
 	pPathSize := alignSize(len(ent.Path))