Consider this:

```
typedef union epoll_data
{
  void *ptr;
  int fd;
  int u32;
  long u64;
} epoll_data_t;

#pragma pack(1)
struct epoll_event
{
  int events;
  epoll_data_t data;
} __EPOLL_PACKED;
```

Jextract generates the following layout for "epoll_event":

```
private static final GroupLayout $LAYOUT = MemoryLayout.structLayout(
        foo_h.C_INT.withByteAlignment(1).withName("events"),
        epoll_data.layout().withName("data")
    ).withName("epoll_event");
```

As can be seen, the "epoll_data" struct field is missing the "withByteAlignment" suffix. This results in a runtime exception when the layout is accessed:

Exception in thread "main" java.lang.ExceptionInInitializerError
at TestGensrc.main(TestGensrc.java:14)
Caused by: java.lang.IllegalArgumentException: Invalid alignment constraint for member layout: [a8(ptr):[*:b1]|i4(fd)|i4(u32)|j8(u64)](data)
at java.base/jdk.internal.foreign.layout.StructLayoutImpl.of(StructLayoutImpl.java:49)
at java.base/java.lang.foreign.MemoryLayout.lambda$structLayout$1(MemoryLayout.java:1063)
at java.base/jdk.internal.foreign.Utils.wrapOverflow(Utils.java:266)
at java.base/java.lang.foreign.MemoryLayout.structLayout(MemoryLayout.java:1062)
at test.epoll_event.<clinit>(epoll_event.java:29)