abi: update libabigail to latest upstream master

This improves the way, libabigail deals with anonymous types and also
introduces speedups for C languague programs such as the Linux Kernel.

Change-Id: Ib9d99d69465800cde26383fe5965827f30002358
Signed-off-by: Matthias Maennich <maennich@google.com>
diff --git a/abi/bootstrap b/abi/bootstrap
index b68a9f8..38af7f4 100755
--- a/abi/bootstrap
+++ b/abi/bootstrap
@@ -15,7 +15,7 @@
 # limitations under the License.
 
 ELFUTILS_VERSION=elfutils-0.176
-ABIGAIL_VERSION=23744b4b
+ABIGAIL_VERSION=2651a362
 
 NUM_CORES=$(cat /proc/cpuinfo | grep -c proc)
 BASE_DIR=$(readlink -f $(dirname $0))