Only throw undefined instruction exception at execution, not at translation stage

Ryujinx/Cpu/State/AInstUndEventArgs.cs

@@ -0,0 +1,16 @@
+using System;
+
+namespace ChocolArm64.State
+{
+    public class AInstUndEventArgs : EventArgs
+    {
+        public long Position  { get; private set; }
+        public int  RawOpCode { get; private set; }
+
+        public AInstUndEventArgs(long Position, int RawOpCode)
+        {
+            this.Position  = Position;
+            this.RawOpCode = RawOpCode;
+        }
+    }
+}