On Alpha and Integrity server systems, creates a virtual region
    within the process's private address space.

    This service accepts 64-bit addresses.

    Format

      SYS$CREATE_REGION_64  length_64 ,region_prot ,flags

                            ,return_region_id_64 ,return_va_64

                            ,return_length_64 [,start_va_64]

    C Prototype

      int sys$create_region_64  ( unsigned __int64 length_64,

                                unsigned int region_prot,

                                unsigned int flags, struct

                                _generic_64 *return_region_id, void

                                *(*(return_va_64)), unsigned __int64

                                *return_length_64,...);