O_DIRECT is missing from correct location in headers

this could possibly be a bug in the man page, but my guess it's in the dev package

man page for open syscall says to include

       #include <sys/types.h>
       #include <sys/stat.h>
       #include <fcntl.h>

simple test program

----
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main()
{
        int fd;

        fd = open("/tmp/123", O_RDWR | O_DIRECT);
}
----

attempt to compile

spotter@dent:/tmp$ gcc test.c
test.c: In function ‘main’:
test.c:9: error: ‘O_DIRECT’ undeclared (first use in this function)
test.c:9: error: (Each undeclared identifier is reported only once
test.c:9: error: for each function it appears in.)

its in asm-generic/fcntl.h which is for some reason not being pulled in, I doubt one is meant to #include <asm/fcntl.h> just to get this defined (especially as it will conflict with <fcntl.h>