Align all message buffers to 64 bytes

This means asking flatbuffers for an aligned pointer in the message
actually works. flatbuffers only aligns relative to the end of the
buffer, and assumes that's aligned enough.

Change-Id: Ia055fddefea277697c37abafbac6f533fb8ec02e
diff --git a/aos/ipc_lib/BUILD b/aos/ipc_lib/BUILD
index 57adc6d..91b050c 100644
--- a/aos/ipc_lib/BUILD
+++ b/aos/ipc_lib/BUILD
@@ -204,6 +204,7 @@
     visibility = ["//visibility:public"],
     deps = [
         ":aos_sync",
+        ":data_alignment",
         ":index",
         "//aos:realtime",
         "//aos/time",
@@ -259,3 +260,14 @@
         "//aos/testing:test_logging",
     ],
 )
+
+cc_library(
+    name = "data_alignment",
+    hdrs = [
+        "data_alignment.h",
+    ],
+    visibility = ["//visibility:public"],
+    deps = [
+        "@com_github_google_glog//:glog",
+    ],
+)