implemented Addwf Instruction (#7)

Co-authored-by: Darkress <30271678+DarkressX@users.noreply.github.com>
Reviewed-on: darkress/pic16f84-sim#7

de/darkress/pic16f84sim/commands/LiteralCommandUtils.java

@@ -0,0 +1,33 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+
+public class LiteralCommandUtils
+{
+    protected void checkZeroBit(int result)
+    {
+        if((result % 256) == 0){
+            Memory.setZeroBit();
+        } else{
+            Memory.clearZeroBit();
+        }
+    }
+
+    protected void checkCarryBit(int result)
+    {
+        if(result > 255){
+            Memory.setCarryBit();
+        } else{
+            Memory.clearCarryBit();
+        }
+    }
+
+    protected void checkDigitCarryBit(int literal)
+    {
+        if(((Memory.workingRegister & 0x0F) + (literal & 0x0F)) > 15){
+            Memory.setDigitCarryBit();
+        } else{
+            Memory.clearDigitCarryBit();
+        }
+    }
+}