restructure: move el compiler content into lang/

lang/tests/calendar/examples/no-cycle.el

@@ -0,0 +1,18 @@
+// no-cycle.el — NoCycleCalendar's cycle_phase returns NaN sentinel.
+// Detection via float_to_str — NaN renders as "nan" under %g.
+
+fn run_test() -> Int {
+    let cal: Calendar = no_cycle_calendar()
+    let i: Instant = unix_seconds(1000000000)
+    let ct: CalendarTime = in_calendar(i, cal)
+    let p: Float = cal_cycle_phase(ct)
+    let s: String = float_to_str(p)
+    if str_eq(s, "nan") {
+        return 1
+    }
+    return 0
+}
+
+fn main() -> Void {
+    println(int_to_str(run_test()))
+}