libg/eglibc: add updated eglibc 2.15

Includes a patch to remove __builtin_expect test:

In eglibc-2.15, the build breaks in configure while testing
for the existance of __builtin_expect. It fails with newer
versions of gcc.

This patch is a modification of an upstream change in glibc
mainline (to be 2.16) to fix the following error:

[CFG ] checking for __builtin_expect... no
[ERROR] configure: error: support for __builtin_expect needed

http://sourceware.org/git/?p=glibc.git;a=commit;h=3857022a761ea7251f8e5c0e45d382ebc3e34cf9

Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
[yann.morin.1998@free.fr: coalesce both patches into a single changeset]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 do not bother running ldconfig on DESTDIR.  it wants to write the temp cache

 file outside of the chroot.  doesnt matter anyways as we wont use the cache

 results (portage will rebuild cache), so running ldconfig is simply a waste

 of time.

 diff -durN glibc-2.12.1.orig/Makefile glibc-2.12.1/Makefile

 --- glibc-2.12.1.orig/Makefile	2009-04-23 20:23:03.000000000 +0200

 +++ glibc-2.12.1/Makefile	2009-11-13 00:49:49.000000000 +0100

 @@ -116,6 +116,7 @@

  	rm -f $(symbolic-link-list)

  install:

 +dont-bother-with-destdir:

  	-test ! -x $(common-objpfx)elf/ldconfig || LC_ALL=C LANGUAGE=C \

  	  $(common-objpfx)elf/ldconfig $(addprefix -r ,$(install_root)) \

  				       $(slibdir) $(libdir)