Function_Variants

   Compiling with the _DECC_V4_SOURCE and _VMS_V6_SOURCE feature-
   test macros defined enables a local-time-based entry point to the
   stat function that is equivalent to the behavior before OpenVMS
   Version 7.0.

   Compiling with the _USE_STD_STAT feature-test macro defined
   enables a variant of the stat function that uses an X/Open
   standard-compliant definition of the stat structure. The _USE_
   STD_STAT feature-test macro is mutually exclusive with the _DECC_
   V4_SOURCE and _VMS_V6_SOURCE macros.