fix a header incompatibility with clang

[TechnoMancer]

This patch fixes an incompatibility with clang it defines ssize_t as in the comment in the file if being compiled with clang.

[TechnoMancer]

patch for supporting clang

[jackburton]

If you see the comment just after the lines you've added, you'll see that we should probably do that regardless of the compiler, and it's gcc's stddef.h which defines ssize_t while it shouldn't.

[TechnoMancer]

That is indeed true, however this makes clang work now. If someone wishes to fix haiku's gcc to not define ssize_t and then make the definition unconditional that is fine and would be appreciated but I am unfamiliar with gcc and would appreciate it if this patch could be applied in the mean time so that clang will work out of the box on haiku.

[jackburton]

Maybe zooey could have a look at what I wrote in comment #1

[kaliber]

According to ​http://www.opengroup.org/onlinepubs/009695399/basedefs/sys/types.h.html ssize_t should be defined in <sys/types.h>

[TechnoMancer]

sys/types.h includes size_t.h to get that def and some others I believe... I think the change should be made there, make the def of ssize_t there unconditional and remove it from gcc's stddef.h

[korli]

Applied a change in hrev37380. I hope it's also valid for clang. Please check.

[TechnoMancer]

It will be as clang pretends to be GCC defining __GNUC__ to be 4

[korli]

Closing then. Reopen if needed.