restructure: move el compiler content into lang/

lang/tests/text/examples/count-lines-words-letters.el

@@ -0,0 +1,16 @@
+// count-lines-words-letters.el — composite count test.
+// Input "Hello world\nGoodbye world\n":
+//   lines:   2 (each \n closes a line)
+//   words:   4 (Hello, world, Goodbye, world)
+//   letters: 22 (Hello=5 + world=5 + Goodbye=7 + world=5)
+fn run_test() -> String {
+    let s: String = "Hello world\nGoodbye world\n"
+    let lines: Int = str_count_lines(s)
+    let words: Int = str_count_words(s)
+    let letters: Int = str_count_letters(s)
+    return int_to_str(lines) + "/" + int_to_str(words) + "/" + int_to_str(letters)
+}
+
+fn main() -> Void {
+    println(run_test())
+}