[MemorySSA] Update analysis when the terminator is a memory instruction.

Update MemorySSA when moving the terminator instruction, as that may be a memory touching instruction.
Resolves PR44029.
diff --git a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
index e55d857..b27e65e 100644
--- a/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopSimplifyCFG.cpp
@@ -662,6 +662,9 @@
     // Merge Succ into Pred and delete it.
     MergeBlockIntoPredecessor(Succ, &DTU, &LI, MSSAU);
 
+    if (MSSAU && VerifyMemorySSA)
+      MSSAU->getMemorySSA()->verifyMemorySSA();
+
     Changed = true;
   }