_BEOS_R5_COMPATIBLE_ was defined in ArchitectureRules while __HAIKU_BEOS_COMPATIBLE is defined in HaikuConfig.h (which is in the include path for sys/types, SupportDefs, and other base headers.)
_BEOS_R5_COMPATIBLE_ was defined in ArchitectureRules while __HAIKU_BEOS_COMPATIBLE is defined in HaikuConfig.h (which is in the include path for sys/types, SupportDefs, and other base headers.)