[Bug preprocessor/64220] gcc preprocessor defines outside of the reserved namespace: unix linux AVR

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64220

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #3)
> https://gcc.gnu.org/onlinedocs/gcc-4.9.2/cpp/System-specific-Predefined-
> Macros.html#System-specific-Predefined-Macros

When the -ansi option, or any -std option that requests strict conformance, is
given to the compiler, all the system-specific predefined macros outside the
reserved namespace are suppressed. The parallel macros, inside the reserved
namespace, remain defined.