one/zero? obs arent handling stuff right, add test. now im setting null on instructions some places they fail

src/test/java/net/runelite/deob/deobfuscators/arithmetic/MultiplyOneDeobfuscatorTest.java

@@ -0,0 +1,80 @@
+package net.runelite.deob.deobfuscators.arithmetic;
+
+import net.runelite.deob.ClassGroup;
+import net.runelite.deob.ClassGroupFactory;
+import net.runelite.deob.Deobfuscator;
+import net.runelite.deob.attributes.Code;
+import net.runelite.deob.attributes.code.Instruction;
+import net.runelite.deob.attributes.code.Instructions;
+import net.runelite.deob.attributes.code.instructions.Goto;
+import net.runelite.deob.attributes.code.instructions.IConst_1;
+import net.runelite.deob.attributes.code.instructions.IConst_2;
+import net.runelite.deob.attributes.code.instructions.IConst_3;
+import net.runelite.deob.attributes.code.instructions.ILoad;
+import net.runelite.deob.attributes.code.instructions.IMul;
+import net.runelite.deob.attributes.code.instructions.IStore_0;
+import net.runelite.deob.attributes.code.instructions.If0;
+import net.runelite.deob.attributes.code.instructions.NOP;
+import net.runelite.deob.attributes.code.instructions.SiPush;
+import net.runelite.deob.attributes.code.instructions.VReturn;
+import net.runelite.deob.execution.Execution;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class MultiplyOneDeobfuscatorTest
+{
+	@Test
+	public void test()
+	{
+		ClassGroup group = ClassGroupFactory.generateGroup();
+		Code code = group.findClass("test").findMethod("func").getCode();
+		Instructions ins = code.getInstructions();
+		
+		code.setMaxStack(2);
+		
+		// vars[0] = 3
+		Instruction[] prepareVariables = {
+			new IConst_3(ins),
+			new IStore_0(ins)
+		};
+		
+		for (Instruction i : prepareVariables)
+			ins.addInstruction(i);
+		
+		NOP label = new NOP(ins),
+		    label2 = new NOP(ins);
+		
+		IConst_1 one = new IConst_1(ins);
+		
+		Instruction body[] = {
+			new SiPush(ins, (short) 256),
+			
+			new ILoad(ins, 0),
+			new If0(ins, label),
+			
+			new IConst_2(ins),
+			new Goto(ins, label2),
+			
+			label,
+			one,
+			
+			label2,
+			new IMul(ins),
+			
+			new VReturn(ins)
+		};
+		
+		for (Instruction i : body)
+			ins.addInstruction(i);
+		
+		// check execution runs ok
+		Execution e = new Execution(group);
+		e.populateInitialMethods();
+		e.run();
+		
+		Deobfuscator d = new MultiplyOneDeobfuscator();
+		d.run(group);
+		
+		Assert.assertTrue(one.getInstructions() != null);
+	}
+}