Modernize libartbase/ usage of <type_traits>... am: 495311c865

Original change: https://android-review.googlesource.com/c/platform/art/+/2063634

Change-Id: Iddb5f661d11de54d4d30c8d8898367db1f52ce1d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>