xstat: only check to see if __ASSUME_ST_INO_64_BIT is defined

We define __ASSUME_ST_INO_64_BIT by default for Linux targets, and then
undef it for alpha/sh targets.  But the code that uses it looks at its
value (as 0/1) rather than whether it's defined (like all other assume
knobs).  Change the code to see if it's defined to fix build Wundef build
errors for alpha/sh.

ChangeLog

@@ -1,4 +1,12 @@
-2016-01-06  Paul Eggert  <eggert@cs.ucla.edu>
+2016-01-07  Mike Frysinger  <vapier@gentoo.org>
+
+	* sysdeps/unix/sysv/linux/fxstat64.c (___fxstat64): Change
+	__ASSUME_ST_INO_64_BIT == 0 to !defined __ASSUME_ST_INO_64_BIT.
+	* sysdeps/unix/sysv/linux/lxstat64.c (___lxstat64): Likewise.
+	* sysdeps/unix/sysv/linux/xstat64.c (___xstat64): Likewise.
+	* sysdeps/unix/sysv/linux/xstatconv.c (__xstat32_conv): Likewise.
+
+2016-01-07  Paul Eggert  <eggert@cs.ucla.edu>
 	    Joseph Myers  <joseph@codesourcery.com>
 
 	* timezone/private.h: Update from tzcode 2015g.

sysdeps/unix/sysv/linux/fxstat64.c

@@ -33,7 +33,7 @@ ___fxstat64 (int vers, int fd, struct stat64 *buf)
 {
   int result;
   result = INLINE_SYSCALL (fstat64, 2, fd, buf);
-#if defined _HAVE_STAT64___ST_INO && __ASSUME_ST_INO_64_BIT == 0
+#if defined _HAVE_STAT64___ST_INO && !defined __ASSUME_ST_INO_64_BIT
   if (__builtin_expect (!result, 1) && buf->__st_ino != (__ino_t) buf->st_ino)
     buf->st_ino = buf->__st_ino;
 #endif

sysdeps/unix/sysv/linux/lxstat64.c

@@ -32,7 +32,7 @@ ___lxstat64 (int vers, const char *name, struct stat64 *buf)
 {
   int result;
   result = INLINE_SYSCALL (lstat64, 2, name, buf);
-#if defined _HAVE_STAT64___ST_INO && __ASSUME_ST_INO_64_BIT == 0
+#if defined _HAVE_STAT64___ST_INO && !defined __ASSUME_ST_INO_64_BIT
   if (__builtin_expect (!result, 1) && buf->__st_ino != (__ino_t) buf->st_ino)
     buf->st_ino = buf->__st_ino;
 #endif

sysdeps/unix/sysv/linux/xstat64.c

@@ -33,7 +33,7 @@ ___xstat64 (int vers, const char *name, struct stat64 *buf)
 {
   int result;
   result = INLINE_SYSCALL (stat64, 2, name, buf);
-#if defined _HAVE_STAT64___ST_INO && __ASSUME_ST_INO_64_BIT == 0
+#if defined _HAVE_STAT64___ST_INO && !defined __ASSUME_ST_INO_64_BIT
   if (__builtin_expect (!result, 1) && buf->__st_ino != (__ino_t) buf->st_ino)
     buf->st_ino = buf->__st_ino;
 #endif

sysdeps/unix/sysv/linux/xstatconv.c

@@ -190,7 +190,7 @@ __xstat32_conv (int vers, struct stat64 *kbuf, struct stat *buf)
 	buf->__pad1 = 0;
 #endif
 #ifdef _HAVE_STAT64___ST_INO
-# if __ASSUME_ST_INO_64_BIT == 0
+# ifndef __ASSUME_ST_INO_64_BIT
 	if (kbuf->st_ino == 0)
 	  buf->st_ino = kbuf->__st_ino;
 	else