implemented Rlf Instruction (#20)

Co-authored-by: Darkress <30271678+DarkressX@users.noreply.github.com>
Reviewed-on: darkress/pic16f84-sim#20

de/darkress/pic16f84sim/commands/Rlf.java

@@ -0,0 +1,36 @@
+package de.darkress.pic16f84sim.commands;
+
+import de.darkress.pic16f84sim.microcontroller.Memory;
+import de.darkress.pic16f84sim.microcontroller.ProgramCounter;
+
+public class Rlf extends FileRegisterCommandUtils implements Command
+{
+    private final int address;
+    private final boolean destinationBit;
+
+    public Rlf(int input)
+    {
+        address = input & 0x007F;
+        destinationBit = checkDestinationBit(input);
+    }
+
+    @Override
+    public void execute()
+    {
+        int register = Memory.getRegister(address);
+        int carry = Memory.getCarryBit();
+        int tmp = carry;
+        carry = register >>7;
+        register = ((register <<1) + tmp) & 0xFF;
+
+        if(carry == 1)
+        {
+            Memory.setCarryBit();
+        } else if(carry == 0){
+            Memory.clearCarryBit();
+        }
+
+        writeToDestination(destinationBit, address, register);
+        ProgramCounter.incPC();
+    }
+}