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.

--- gcc-4.2.1-stock/gcc/config/alpha/linux-unwind.h	2005-06-24 20:22:41.000000000 -0500

+++ gcc-4.2.1/gcc/config/alpha/linux-unwind.h	2007-09-01 20:21:34.000000000 -0500

@@ -29,6 +29,9 @@ Boston, MA 02110-1301, USA.  */

 /* Do code reading to identify a signal frame, and set the frame

    state data appropriately.  See unwind-dw2.c for the structs.  */

+/* Don't use this if inhibit_libc is set

+   The build for this target will fail trying to include missing headers */

+#ifndef inhibit_libc

 #include <signal.h>

 #include <sys/ucontext.h>

@@ -80,3 +83,4 @@ alpha_fallback_frame_state (struct _Unwi

   fs->retaddr_column = 64;

   return _URC_NO_REASON;

 }

+#endif /* inhibit_libc */