svn commit: r202628 - in head: . sys/amd64/amd64 sys/i386/i386 sys/i386/xen sys/sys

[David Schultz]

__gnu89_inline was the only way to write a program with non-static
inline functions that would compile and link both with older versions
of gcc, and with newer versions of gcc in C99 mode.  This is because
gcc in 8.x (as well as Clang and gcc 4.3+ from ports) use C99 inline
semantics in the c99 and gnu99 modes, whereas gcc in 7.x and earlier
use the incompatible GNU semantics regardless of what mode you asked
for.

A small number of ports might use it, but more likely they just use
--std=gnu89 or --std=gnu99 depending on which standard they were
written to.  I'm not sure whether __gnu89_inline ought to be removed
from cdefs.h just yet, but if nobody uses it or cares about it, then
I'm happy to burn this bridge.