[AMDGPU][AtomicOptimizer] Fix DT update for divergent values with Iterative strategy (#87605)

We take the terminator from EntryBB and put it in ComputeEnd. Make sure
we also move the DT edges, we previously only did it assuming a
non-conditional branch.

Fixes SWDEV-453943

GitOrigin-RevId: fcdb2203e05002f0488221f6a0cab42e1a34f8fc
2 files changed