win,fs: avoid winapi macro redefinition (libuv#4123)

Adjust include order to avoid redefining `CTL_CODE`, `FILE_READ_ACCESS`,
and `FILE_WRITE_ACCESS`.  Without this, compilation shows:

```
...\um\winioctl.h(273): warning C4005: 'CTL_CODE': macro redefinition
...\src\win\winapi.h(4497): note: see previous definition of 'CTL_CODE'

...\um\winioctl.h(320): warning C4005: 'FILE_READ_ACCESS': macro redefinition
...\src\win\winapi.h(4488): note: see previous definition of 'FILE_READ_ACCESS'

...\um\winioctl.h(321): warning C4005: 'FILE_WRITE_ACCESS': macro redefinition
...\src\win\winapi.h(4492): note: see previous definition of 'FILE_WRITE_ACCESS'
```

src/win/fs.c

@@ -31,13 +31,16 @@
 #include <stdio.h>
 
 #include "uv.h"
+
+/* <winioctl.h> requires <windows.h>, included via "uv.h" above, but needs to
+   be included before our "winapi.h", included via "internal.h" below. */
+#include <winioctl.h>
+
 #include "internal.h"
 #include "req-inl.h"
 #include "handle-inl.h"
 #include "fs-fd-hash-inl.h"
 
-#include <winioctl.h>
-
 
 #define UV_FS_FREE_PATHS         0x0002
 #define UV_FS_FREE_PTR           0x0008