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/fib.myc

@@ -1,12 +1,11 @@
 ;; Fibonacci Recursive
-;; Benchmark: 33.3us
-;; Benchmark-Repeat: 63
-;; Output: 55
+;; Benchmark: 37.1us
+;; Benchmark-Repeat: 55
 (do
   (def fib (fn [n]
     (if (< n 2)
       n
       (+ (fib (- n 1)) (fib (- n 2))))))
 
-  (fib 10)
+  (assert-eq 55 (fib 10))
 )