Authorizes a new branch to be added to a transaction. $ADD_
    BRANCHW always waits for the request to complete before returning
    to the caller. Other than this, it is identical to $ADD_BRANCH.

    Format

      SYS$ADD_BRANCHW  [efn] ,[flags] ,iosb ,[astadr] ,[astprm] ,tid

                       ,tm_name ,bid

    C Prototype

      int sys$add_branchw  (unsigned int efn, unsigned int

                           flags, struct _iosb *iosb, void

                           (*astadr)(__unknown_params), int astprm,

                           unsigned int tid [4], void *tmname,

                           unsigned int bid [4]);