ART: Remove old DCHECK that trips Baseline

Codegen verified that the entry block always falls through to the next
block. While this is the case with Optimizing, it doesn't hold for
Baseline but it doesn't need to since codegen handles it fine.

Bug:21913514
Change-Id: I751ef227e6cf103af3e7fc35fca4b01c663385a1
5 files changed