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/macro_hygiene.myc

@@ -1,9 +1,8 @@
-;; Benchmark: 176ns
-;; Benchmark-Repeat: 11632
-;; Output: 5
+;; Benchmark: 268ns
+;; Benchmark-Repeat: 7910
 (do
 (def y 1)
 (macro m1 [x] `(do (def y 10) (assign y 4)))
 (m1 8)
-(+ y (m1 8))
+(assert-eq 5 (+ y (m1 8)))
 )