basic packed struct support

type.c

 	struct tfield *f;
 	ssize_t falign, align = -EINVAL;
 
+	if (t->sou.packed)
+		return 1;
+
 	tfields_foreach(f, t->sou.fields) {
 		falign = type_alignof(f->type);
 

type_test.c

 	int   b[5];
 	char  c[3];
 	short d;
-} *t1 = NULL;
+};
 
 static int struct_basic(void *_null)
 {
 }
 UNITTEST(struct_basic);
 
+struct t1_packed {
+	char  a;
+	int   b[5];
+	char  c[3];
+	short d;
+} __attribute__((packed));
+
+static int struct_packed(void *_null)
+{
+	struct tfield t1_fields[] = {
+		{ .name = "a", .type = &t_char },
+		{ .name = "b", .type = type_array_of(&t_int, 5) },
+		{ .name = "c", .type = type_array_of(&t_char, 3) },
+		{ .name = "d", .type = &t_short },
+
+		{ .type = &t_void }
+	};
+	struct type t_t1 = {
+		.ttype = T_STRUCT,
+		.sou = { .name = "t1", .fields = t1_fields, .packed = 1 },
+	};
+
+	unittest_eq(type_offsetof(&t_t1, "a"), offsetof(struct t1_packed, a));
+	unittest_eq(type_offsetof(&t_t1, "b"), offsetof(struct t1_packed, b));
+	unittest_eq(type_offsetof(&t_t1, "c"), offsetof(struct t1_packed, c));
+	unittest_eq(type_offsetof(&t_t1, "d"), offsetof(struct t1_packed, d));
+
+	unittest_eq(type_alignof(&t_t1), __alignof__(struct t1_packed));
+	unittest_eq(type_sizeof(&t_t1), sizeof(struct t1_packed));
+	return 0;
+}
+UNITTEST(struct_packed);
+
 int main(void)
 {
 	struct unittest_ctx ctx = {