[Bug target/65128] remove "linux" and "unix" from preprocessor macros from cpp-5

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65128

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |*-*-linux, *-*-unix,
                   |                            |*-*-sun
          Component|preprocessor                |target

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
They are indeed legacy defines.  More affected systems:

dragonfly.h:       builtin_define_std ("unix");         \
freebsd-spec.h: builtin_define_std ("unix");                                  
\
gnu.h:  builtin_define_std ("unix");            \
kfreebsd-gnu.h: builtin_define_std ("unix");            \
knetbsd-gnu.h:  builtin_define_std ("unix");            \
kopensolaris-gnu.h:     builtin_define_std ("unix");            \
linux.h:        builtin_define_std ("linux");                           \
linux.h:        builtin_define_std ("unix");                            \
sol2.h: builtin_define_std ("unix");                    \
sol2.h: builtin_define_std ("sun");                     \