libc/uClibc: fix building on system with recent glibc

While trying to build a toolchain with ct-ng 1.5.0,
arm-unknown-linux-uclibcgnueabi target,
I get the following error:

[INFO ] Installing C library headers
[EXTRA] Copying sources to build dir
[EXTRA] Applying configuration
[EXTRA] Building headers
[EXTRA] Installing headers
[ERROR] extra/scripts/unifdef.c:209: error: conflicting types for 'getline'
[ERROR] make[2]: *** [extra/scripts/unifdef] Error 1
[ERROR] Build failed in step 'Installing C library headers'

The following patch solves the problem.
(It's a backport of this uClibc commit:
http://git.uclibc.org/uClibc/commit/?id=49e81cada73616864b9b31df0aeb6961c30f5a6e
)

[--SNIP from another mail--]
AFAIK this is a problem since glibc 2.10.
(transplanted from 1ba79f2126df8bd89120899a58f2d0bcc2e9c771)

2008-06-07  Mike Frysinger  <vapier@gentoo.org>

	* sysdeps/unix/sysv/linux/alpha/sys/user.h: Copy page.h definitions

	from the kernel header to sys/user.h and remove the #include of

	sys/user.h.

--- a/sysdeps/unix/sysv/linux/alpha/sys/user.h

+++ b/sysdeps/unix/sysv/linux/alpha/sys/user.h

@@ -23,7 +23,6 @@

    only. Don't read too much into it. Don't use it for anything other

    than gdb/strace unless you know what you are doing. */

-#include <asm/page.h>

 #include <asm/reg.h>

 struct user

@@ -41,6 +40,9 @@ struct user

   char u_comm[32];				/* user command name */

 };

+#define PAGE_SHIFT		13

+#define PAGE_SIZE		(1 << PAGE_SHIFT)

+#define PAGE_MASK		(~(PAGE_SIZE-1))

 #define NBPG			PAGE_SIZE

 #define UPAGES			1

 #define HOST_TEXT_START_ADDR	(u.start_code)