Implemented data labels

src/build/asm/Label.go

@@ -9,3 +9,13 @@ type Label struct {
 func (data *Label) String() string {
 	return data.Name
 }
+
+// Label adds an instruction using a label.
+func (a *Assembler) Label(mnemonic Mnemonic, name string) {
+	a.Instructions = append(a.Instructions, Instruction{
+		Mnemonic: mnemonic,
+		Data: &Label{
+			Name: name,
+		},
+	})
+}