implement shift and rotate handlers. Fix tests

X86Disassembler/X86/Handlers/Shift/RclRm8ByImmHandler.cs

@@ -0,0 +1,72 @@
+using X86Disassembler.X86.Operands;
+
+namespace X86Disassembler.X86.Handlers.Shift;
+
+/// <summary>
+/// Handler for RCL r/m8, imm8 instruction (0xC0 /2)
+/// </summary>
+public class RclRm8ByImmHandler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the RclRm8ByImmHandler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public RclRm8ByImmHandler(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)
+    {
+        // RCL r/m8, imm8 is encoded as 0xC0 /2
+        if (opcode != 0xC0)
+            return false;
+
+        // Check if we can read the ModR/M byte
+        if (!Decoder.CanReadByte())
+            return false;
+
+        // Check if the reg field of the ModR/M byte is 2 (RCL)
+        var reg = ModRMDecoder.PeakModRMReg();
+        return reg == 2; // 2 = RCL
+    }
+
+    /// <summary>
+    /// Decodes a RCL r/m8, imm8 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.Rcl;
+
+        // Read the ModR/M byte
+        var (_, _, _, operand) = ModRMDecoder.ReadModRM8();
+
+        // Check if we can read the immediate byte
+        if (!Decoder.CanReadByte())
+            return false;
+
+        // Read the immediate byte (rotate count)
+        byte imm8 = Decoder.ReadByte();
+
+        // Create an immediate operand for the rotate count
+        var immOperand = OperandFactory.CreateImmediateOperand(imm8);
+
+        // Set the structured operands
+        instruction.StructuredOperands = 
+        [
+            operand,
+            immOperand
+        ];
+
+        return true;
+    }
+}