H5O_info[1]_t type definition is incorrect

[mkitti]

In working through #979 I discovered that our H5O_info[1]_t definition is incorrect.

https://cs.github.com/HDFGroup/hdf5/blob/c064d3481b582653c1e0d0043a17527fd73e8c4d/src/H5Opublic.h#L1690

typedef struct H5O_info1_t {
    unsigned long  fileno;    /**< File number that object is located in */
    haddr_t        addr;      /**< Object address in file                */
    H5O_type_t     type;      /**< Basic object type (group, dataset, etc.) */
    unsigned       rc;        /**< Reference count of object    */
    time_t         atime;     /**< Access time                  */
    time_t         mtime;     /**< Modification time            */
    time_t         ctime;     /**< Change time                  */
    time_t         btime;     /**< Birth time                   */
    hsize_t        num_attrs; /**< Number of attributes attached to object */
    H5O_hdr_info_t hdr;       /**< Object header information */
    /* Extra metadata storage for obj & attributes */
    struct {
        H5_ih_info_t obj;  /**< v1/v2 B-tree & local/fractal heap for groups, B-tree for chunked datasets */
        H5_ih_info_t attr; /**< v2 B-tree & heap for attributes */
    } meta_size;
} H5O_info1_t;

• fileno should be Culong
• otype should be type

https://github.com/JuliaIO/HDF5.jl/blob/master/src/api/types.jl#L66-L92

The current version works due to padding. fieldoffset(H5O_info_t, 2) yields 8 regardless of the type of fileno.

julia> fieldoffset(HDF5.API.H5O_info_t, 2)
0x0000000000000008