Implemented if statements

src/build/asm/Instructions.go

@@ -34,10 +34,10 @@ func (a *Assembler) Register(mnemonic Mnemonic, register cpu.Register) {
 	})
 }
 
-// Label adds a label at the current position.
-func (a *Assembler) Label(name string) {
+// Label adds an instruction using a label.
+func (a *Assembler) Label(mnemonic Mnemonic, name string) {
 	a.Instructions = append(a.Instructions, Instruction{
-		Mnemonic: LABEL,
+		Mnemonic: mnemonic,
 		Data: &Label{
 			Name: name,
 		},