Refactor Examples to use assert_eq

This commit updates all example files to use `assert_eq!` for verifying
output, replacing the previous `Output:` comments. This change makes the
examples more robust and self-testing.

The benchmark results in some examples have also been slightly adjusted,
reflecting minor performance variations after the refactoring.

Additionally, a runtime panic handling mechanism has been introduced in
the VM for function calls, which improves error reporting for unexpected
panics.

examples/again.myc

@@ -1,10 +1,9 @@
-;; Benchmark: 1.2us
-;; Benchmark-Repeat: 1658
-;; Output: 120
+;; Benchmark: 1.5us
+;; Benchmark-Repeat: 1306
 (do
   (def factorial (fn [n acc]
     (if (= n 0)
       acc
       (again (- n 1) (* acc n)))))
 
-  (factorial 5 1))
+  (assert-eq 120 (factorial 5 1)))