Add missing handling of x instruction

src/codebox.ts

@@ -316,6 +316,10 @@ export class CodeBox {
                 this.omniMirror();
                 break;
             }
+            case InstructionDictionary.MIRROR_RANDOM: {
+                this.pointer.shuffleDirection();
+                break;
+            }
             // Trampolines
             case InstructionDictionary.TRAMPOLINE_CLASSIC: {
                 this.pointer.move();