add test for function evaluation order (see #4787)

tests/unit/src/unitstd/EvaluationOrder.unit.hx

@@ -115,4 +115,18 @@ function idx(x, y) {
 
 var end = begin();
 var _ = (arr(a(), b()))[idx(c(), d())];
-eq(end(), "1_2_3_4");
+eq(end(), "1_2_3_4");
+
+function f1() {
+	buf.push(1);
+	return function(i) { };
+}
+
+function f2() {
+	buf.push(2);
+	return 2;
+}
+
+var end = begin();
+f1()(f2());
+eq(end(), "1_2");