Make SH <sys/user.h> self-contained

[Joseph Myers]

The check-installed-headers tests show up that the SH <sys/user.h> is
not self-contained, using size_t without including any header that
defines it.  This patch fixes it by including <stddef.h>, as done for
other architectures' versions of this header.

Tested for SH3 and SH4 (compilation only).

2016-11-04  Joseph Myers  <joseph@codesourcery.com>

	* sysdeps/unix/sysv/linux/sh/sys/user.h: Include <stddef.h>.

diff --git a/sysdeps/unix/sysv/linux/sh/sys/user.h b/sysdeps/unix/sysv/linux/sh/sys/user.h
index 47b87ae..2999b03 100644
--- a/sysdeps/unix/sysv/linux/sh/sys/user.h
+++ b/sysdeps/unix/sysv/linux/sh/sys/user.h
@@ -19,6 +19,7 @@
 #define _SYS_USER_H	1
 
 #include <asm/ptrace.h>
+#include <stddef.h>
 
 /* asm/ptrace.h polutes the namespace.  */
 #undef PTRACE_GETREGS

-- 
Joseph S. Myers
joseph@codesourcery.com