Fix all tests

X86Disassembler/X86/Handlers/Xchg/XchgR8Rm8Handler.cs

@@ -0,0 +1,66 @@
+using X86Disassembler.X86.Operands;
+
+namespace X86Disassembler.X86.Handlers.Xchg;
+
+/// <summary>
+/// Handler for XCHG r8, r/m8 instruction (opcode 0x86)
+/// Exchanges the contents of an 8-bit register with a register or memory location
+/// </summary>
+public class XchgR8Rm8Handler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the XchgR8Rm8Handler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public XchgR8Rm8Handler(InstructionDecoder decoder)
+        : base(decoder)
+    {
+    }
+
+    /// <summary>
+    /// Checks if this handler can decode the given opcode
+    /// </summary>
+    /// <param name="opcode">The opcode to check</param>
+    /// <returns>True if this handler can decode the opcode</returns>
+    public override bool CanHandle(byte opcode)
+    {
+        // XCHG r8, r/m8 is 0x86
+        return opcode == 0x86;
+    }
+    
+    /// <summary>
+    /// Decodes an XCHG r8, r/m8 instruction
+    /// </summary>
+    /// <param name="opcode">The opcode of the instruction</param>
+    /// <param name="instruction">The instruction object to populate</param>
+    /// <returns>True if the instruction was successfully decoded</returns>
+    public override bool Decode(byte opcode, Instruction instruction)
+    {
+        // Set the instruction type
+        instruction.Type = InstructionType.Xchg;
+        
+        // Check if we have enough bytes for the ModR/M byte
+        if (!Decoder.CanReadByte())
+        {
+            return false;
+        }
+        
+        // Read the ModR/M byte
+        // For XCHG r8, r/m8 (0x86):
+        // - The reg field specifies the first register operand
+        // - The r/m field with mod specifies the second operand (register or memory)
+        var (_, reg, _, destinationOperand) = ModRMDecoder.ReadModRM8();
+        
+        // Create the source register operand from the reg field
+        var sourceOperand = OperandFactory.CreateRegisterOperand8(reg);
+        
+        // Set the structured operands
+        instruction.StructuredOperands = 
+        [
+            destinationOperand,
+            sourceOperand
+        ];
+        
+        return true;
+    }
+}