fix linker failure with newer binutils

http://bugs.gentoo.org/258072

commit 9ec3d5f8d876b07747fd49827e2cef8286b6f4cd
Author: Ulrich Drepper <drepper@redhat.com>
Date:   Sat Jan 31 00:20:55 2009 +0000

    (ld.so): Adjust the sed script to insert _begin in to newer linker scripts.

diff --git a/elf/Makefile b/elf/Makefile
index 8079fe9..e44ff1d 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -304,7 +304,7 @@ $(objpfx)ld.so: $(objpfx)librtld.os $(ld-map)
 		  $(LDFLAGS-rtld) -Wl,-z,defs -Wl,--verbose 2>&1 |	\
 		  LC_ALL=C \
 		  sed -e '/^=========/,/^=========/!d;/^=========/d'	\
-		      -e 's/\. = 0 + SIZEOF_HEADERS;/& _begin = . - SIZEOF_HEADERS;/' \
+		      -e 's/\. = .* + SIZEOF_HEADERS;/& _begin = . - SIZEOF_HEADERS;/' \
 		  > $@.lds
 	$(LINK.o) -nostdlib -nostartfiles -shared -o $@			\
 		  $(LDFLAGS-rtld) -Wl,-z,defs $(z-now-$(bind-now))	\