Remove instructions from dead blocks when building the dominator tree am: 7023bf8227 am: 8880c14298 am: 4adb3eb29b am: 65d72a1c79

Original change: https://android-review.googlesource.com/c/platform/art/+/2190021

Change-Id: Id73317329995f50bcf3427d9686fc1dcbcba363d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>