moved benchmark lox files to separate folder

benchmark/trees.lox

@@ -0,0 +1,29 @@
+class Tree {
+  init(depth) {
+    this.depth = depth;
+    if (depth > 0) {
+      this.a = Tree(depth - 1);
+      this.b = Tree(depth - 1);
+      this.c = Tree(depth - 1);
+      this.d = Tree(depth - 1);
+      this.e = Tree(depth - 1);
+    }
+  }
+
+  walk() {
+    if (this.depth == 0) return 0;
+    return this.depth 
+        + this.a.walk()
+        + this.b.walk()
+        + this.c.walk()
+        + this.d.walk()
+        + this.e.walk();
+  }
+}
+
+var tree = Tree(8);
+var start = clock();
+for (var i = 0; i < 100; i = i + 1) {
+  if (tree.walk() != 122068) print "Error";
+}
+print clock() - start;