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

[shawn at churchofgit dot com]

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

--- Comment #3 from Shawn Landden <shawn at churchofgit dot com> ---
Created attachment 34892
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34892&action=edit
remove legacy includes