olddefconfig exists in 3.8, so we should be able to just replace 'oldnoconfig' with 'olddefconfig' in the build scripts.

Will do.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/9498f0d36ca96dc906be71945f19b3f720bae822

commit 9498f0d36ca96dc906be71945f19b3f720bae822
Author: Ross Zwisler <zwisler@google.com>
Date: Thu Oct 11 00:07:56 2018

cros-kernel2: use olddefconfig instead of oldnoconfig

When building with v4.19 based kernels we see:

  WARNING: "oldnoconfig" target will be removed after Linux 4.19
            Please use "olddefconfig" instead, which is an alias.

The olddefconfig target is present in all the kernels we need to support
so just move to it unconditionally for all kernel builds.

BUG= chromium:893308 
TEST=emerge-samus sys-kernel/chromeos-kernel-next

Change-Id: Id79daf6faa15ea088499fa8941f1fb45b661a5fe
Signed-off-by: Ross Zwisler <zwisler@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1272155
Commit-Ready: Ross Zwisler <zwisler@chromium.org>
Tested-by: Ross Zwisler <zwisler@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>

[modify] https://crrev.com/9498f0d36ca96dc906be71945f19b3f720bae822/eclass/cros-kernel2.eclass

Fixed with the commit referenced in comment #3.