printing: commit some refactors (probably broken)

examples/add/add_test.go

@@ -0,0 +1,12 @@
+package add
+
+import (
+	"testing"
+	"testing/quick"
+)
+
+//go:generate go run asm.go -out add.s -stubs stub.go
+
+func TestAdd(t *testing.T) {
+	quick.CheckEqual(Add, func(x, y uint64) uint64 { return x + y }, nil)
+}