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.

Change-Id: I751ef227e6cf103af3e7fc35fca4b01c663385a1
(cherry picked from commit 015c7e63604c038e866d7af3850c557403cddc8b)
5 files changed