Always include <sys/cdefs.h> first.

Otherwise you can't be sure that things like __BIONIC__ work.

Change-Id: Ic5e59988b69419828c3b1a97332c7e2ab58e09a1
diff --git a/libc/include/sys/param.h b/libc/include/sys/param.h
index 1c991ae..99b6a07 100644
--- a/libc/include/sys/param.h
+++ b/libc/include/sys/param.h
@@ -33,10 +33,11 @@
  * @brief Various macros.
  */
 
+#include <sys/cdefs.h>
+
 #include <endian.h>
 #include <limits.h>
 #include <linux/param.h>
-#include <sys/cdefs.h>
 
 /** The unit of `st_blocks` in `struct stat`. */
 #define DEV_BSIZE 512
diff --git a/libc/include/sys/stat.h b/libc/include/sys/stat.h
index 2633b69..ed52bcc 100644
--- a/libc/include/sys/stat.h
+++ b/libc/include/sys/stat.h
@@ -33,9 +33,10 @@
  * @brief File status.
  */
 
+#include <sys/cdefs.h>
+
 #include <bits/timespec.h>
 #include <linux/stat.h>
-#include <sys/cdefs.h>
 #include <sys/types.h>
 
 __BEGIN_DECLS
diff --git a/libc/include/sys/statvfs.h b/libc/include/sys/statvfs.h
index 2feca81..860824b 100644
--- a/libc/include/sys/statvfs.h
+++ b/libc/include/sys/statvfs.h
@@ -21,8 +21,9 @@
  * @brief Filesystem statistics.
  */
 
-#include <stdint.h>
 #include <sys/cdefs.h>
+
+#include <stdint.h>
 #include <sys/types.h>
 
 __BEGIN_DECLS
diff --git a/libc/include/sys/syscall.h b/libc/include/sys/syscall.h
index a49323d..9341ffb 100644
--- a/libc/include/sys/syscall.h
+++ b/libc/include/sys/syscall.h
@@ -29,9 +29,10 @@
 #ifndef _SYS_SYSCALL_H_
 #define _SYS_SYSCALL_H_
 
+#include <sys/cdefs.h>
+
 #include <asm/unistd.h> /* Linux kernel __NR_* names. */
 #include <bits/glibc-syscalls.h> /* glibc-compatible SYS_* aliases. */
-#include <sys/cdefs.h>
 
 /* The syscall function itself is declared in <unistd.h>, not here. */
 
diff --git a/libc/include/sys/timerfd.h b/libc/include/sys/timerfd.h
index bfa9a55..f7f1ffa 100644
--- a/libc/include/sys/timerfd.h
+++ b/libc/include/sys/timerfd.h
@@ -33,10 +33,11 @@
  * @brief Timer file descriptors.
  */
 
+#include <sys/cdefs.h>
+
 #include <fcntl.h>
 #include <linux/timerfd.h>
 #include <time.h>
-#include <sys/cdefs.h>
 #include <sys/types.h>
 
 __BEGIN_DECLS
diff --git a/libc/include/sys/types.h b/libc/include/sys/types.h
index 4622a4e..0446260 100644
--- a/libc/include/sys/types.h
+++ b/libc/include/sys/types.h
@@ -29,9 +29,10 @@
 #ifndef _SYS_TYPES_H_
 #define _SYS_TYPES_H_
 
+#include <sys/cdefs.h>
+
 #include <stddef.h>
 #include <stdint.h>
-#include <sys/cdefs.h>
 
 #include <linux/types.h>
 #include <linux/posix_types.h>
diff --git a/libc/include/sys/un.h b/libc/include/sys/un.h
index 83c1d17..c2bfcb0 100644
--- a/libc/include/sys/un.h
+++ b/libc/include/sys/un.h
@@ -33,9 +33,10 @@
  * @brief Unix domain sockets.
  */
 
+#include <sys/cdefs.h>
+
 #include <bits/sa_family_t.h>
 #include <linux/un.h>
-#include <sys/cdefs.h>
 
 #if defined(__USE_BSD) || defined(__USE_GNU)
 #include <string.h>
diff --git a/libc/include/sys/vfs.h b/libc/include/sys/vfs.h
index 1a640ba..5d078be 100644
--- a/libc/include/sys/vfs.h
+++ b/libc/include/sys/vfs.h
@@ -29,8 +29,9 @@
 #ifndef _SYS_VFS_H_
 #define _SYS_VFS_H_
 
-#include <stdint.h>
 #include <sys/cdefs.h>
+
+#include <stdint.h>
 #include <sys/types.h>
 
 __BEGIN_DECLS
diff --git a/libc/include/sys/wait.h b/libc/include/sys/wait.h
index 5208366..632aa43 100644
--- a/libc/include/sys/wait.h
+++ b/libc/include/sys/wait.h
@@ -28,8 +28,9 @@
 
 #pragma once
 
-#include <bits/wait.h>
 #include <sys/cdefs.h>
+
+#include <bits/wait.h>
 #include <sys/types.h>
 #include <sys/resource.h>
 #include <linux/wait.h>
diff --git a/libc/include/sys/xattr.h b/libc/include/sys/xattr.h
index 38c11e2..ebe4eb8 100644
--- a/libc/include/sys/xattr.h
+++ b/libc/include/sys/xattr.h
@@ -33,8 +33,9 @@
  * @brief Extended attribute functions.
  */
 
-#include <linux/xattr.h>
 #include <sys/cdefs.h>
+
+#include <linux/xattr.h>
 #include <sys/types.h>
 
 __BEGIN_DECLS