Add prelude and while macro

This commit introduces a new prelude file that defines the `while` macro
and registers it during environment bootstrapping. The `again` macro has
been updated to accept multiple arguments for its recursive call, and
several examples have been adjusted to reflect this change.
Additionally, the `MacroRegistry` in the compiler is now cloneable and
can be moved out of the `MacroExpander`.

examples/again.myc

@@ -1,10 +1,10 @@
-;; Benchmark: 2.5us
-;; Benchmark-Repeat: 804
+;; Benchmark: 2.5us
+;; Benchmark-Repeat: 804
 ;; Output: 120
 (do
   (def factorial (fn [n acc]
     (if (= n 0)
       acc
-      (again [(- n 1) (* acc n)]))))
+      (again (- n 1) (* acc n)))))
 
   (factorial 5 1))

examples/record_optimizations.myc

@@ -1,21 +1,12 @@
 ;; Benchmark: 1.7ms
 ;; Benchmark-Repeat: 3
-;; Benchmark: TBD
-;; Tests the effect of record inlining and field lookup optimization
-;; Output: 10000
-(do
-  (macro while [cond body]
-    `(do
-       (def _while_loop (fn []
-         (if ~cond
-             (do ~body (_while_loop))
-             ...)))
-       (_while_loop)))
-
-  (def config {:start 0 :limit 10000 :step 2})
-  (def x (.start config))
-
-  (while (< x (.limit config))
-         (assign x (+ x (.step config))))
-  x
-)
+;; Tests the effect of record inlining and field lookup optimization
+;; Output: 10000
+(do
+  (def config {:start 0 :limit 10000 :step 2})
+  (def x (.start config))
+
+  (while (< x (.limit config))
+         (assign x (+ x (.step config))))
+  x
+)