cgen: fix in array_of_ref_structs (fix #7623) (#7640)

vlib/builtin/array_test.v

@@ -1251,7 +1251,7 @@ struct Coord {
 	z int
 }
 
-fn test__array_struct_contains() {
+fn test_array_struct_contains() {
 	mut coords := []Coord{}
 	coord_1 := Coord{
 		x: 1
@@ -1265,3 +1265,16 @@ fn test__array_struct_contains() {
 	assert exists == true
 	assert not_exists == false
 }
+
+fn test_array_struct_ref_contains() {
+	mut coords := []&Coord{}
+	coord_1 := &Coord{
+		x: 1
+		y: 2
+		z: -1
+	}
+	coords << coord_1
+	exists := coord_1 in coords
+	println(exists)
+	assert exists == true
+}