Remove __ASSUME_PPOLL.

With current kernel version requirements, the ppoll Linux syscall can
be assumed to be present on all architectures; this patch removes the
__ASSUME_PPOLL macro and conditionals on it and on whether __NR_ppoll
is defined.  (Note that the same can't yet be done for pselect,
because MicroBlaze only wired that up in the syscall table in 3.15.)

Tested for x86_64 and x86 that installed stripped shared libraries are
unchanged by the patch.

	* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_PPOLL):
	Remove macro.
	* sysdeps/unix/sysv/linux/ppoll.c: Do not include
	<kernel-features.h>.
	[__NR_ppoll]: Make code unconditional.
	[!__ASSUME_PPOLL]: Remove conditional code.

ChangeLog

@@ -1,5 +1,12 @@
 2016-03-15  Joseph Myers  <joseph@codesourcery.com>
 
+	* sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_PPOLL):
+	Remove macro.
+	* sysdeps/unix/sysv/linux/ppoll.c: Do not include
+	<kernel-features.h>.
+	[__NR_ppoll]: Make code unconditional.
+	[!__ASSUME_PPOLL]: Remove conditional code.
+
 	* sysdeps/unix/sysv/linux/kernel-features.h
 	(__ASSUME_ACCEPT4_SYSCALL): Define unconditionally.
 	(__ASSUME_ACCEPT4): Likewise.

sysdeps/unix/sysv/linux/kernel-features.h

@@ -58,7 +58,6 @@
 /* pselect/ppoll were introduced just after 2.6.16-rc1.  On x86_64 and
    SH this appeared first in 2.6.19-rc1, on ia64 in 2.6.22-rc1.  */
 #define __ASSUME_PSELECT	1
-#define __ASSUME_PPOLL		1
 
 /* The *at syscalls were introduced just after 2.6.16-rc1.  On PPC
    they were introduced in 2.6.17-rc1, on SH in 2.6.19-rc1.  */

sysdeps/unix/sysv/linux/ppoll.c

@@ -20,18 +20,9 @@
 #include <signal.h>
 #include <time.h>
 #include <sys/poll.h>
-#include <kernel-features.h>
 #include <sysdep-cancel.h>
 
 
-#ifdef __NR_ppoll
-# ifndef __ASSUME_PPOLL
-static int __generic_ppoll (struct pollfd *fds, nfds_t nfds,
-			    const struct timespec *timeout,
-			    const sigset_t *sigmask);
-# endif
-
-
 int
 ppoll (struct pollfd *fds, nfds_t nfds, const struct timespec *timeout,
        const sigset_t *sigmask)
@@ -45,24 +36,6 @@ ppoll (struct pollfd *fds, nfds_t nfds, const struct timespec *timeout,
       timeout = &tval;
     }
 
-  int result;
-
-  result = SYSCALL_CANCEL (ppoll, fds, nfds, timeout, sigmask, _NSIG / 8);
-
-# ifndef __ASSUME_PPOLL
-  if (result == -1 && errno == ENOSYS)
-    result = __generic_ppoll (fds, nfds, timeout, sigmask);
-# endif
-
-  return result;
+  return SYSCALL_CANCEL (ppoll, fds, nfds, timeout, sigmask, _NSIG / 8);
 }
 libc_hidden_def (ppoll)
-
-# ifndef __ASSUME_PPOLL
-#  define ppoll static __generic_ppoll
-# endif
-#endif
-
-#ifndef __ASSUME_PPOLL
-# include <io/ppoll.c>
-#endif