Added typeof opcode to verify variable types.

examples/typeof.fun

@@ -0,0 +1,50 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://hanez.org/project/fun/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the ISC license.
+ * https://opensource.org/license/isc-license-txt
+ */
+
+print("=== Typeof test start ===")
+ 
+ // Array
+a = [1, 2, 3]
+print(typeof(a))
+ 
+fun f()
+  print("A function!")
+
+// Function
+print(typeof(f))
+f()
+
+// Map
+m = { "x": 1, "y": 2, "move": move }
+print(typeof(m))
+
+// Nil
+nil x = nil
+print(typeof(x))
+
+// Number
+number n = 10
+print(typeof(n)) 
+
+string s = "Have fun!"
+print(typeof(s)) 
+
+print("=== Typeof test end ===")
+
+/* Expected output:
+Array
+Function
+A function!
+Map
+Nil
+Number
+String
+*/