eigen: Backport an upstream fix

Backport upstream patch to fix some build errors
in opencv.

BUG=chromium:1059030
TEST=eigen builds, opencv errors are reduced.

Change-Id: I162bb51a6831cc102423d20ab857b3fb4a10e178
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2090087
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Caroline Tice <cmtice@chromium.org>
Commit-Queue: Manoj Gupta <manojgupta@chromium.org>
2 files changed