JumpThreadingPass::UnfoldSelectInstr - silence static analyzer dyn_cast<> null dereference warning. NFCI.

The static analyzer is warning about a potential null dereference, but we should be able to use cast<> directly and if not assert will fire for us.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375103 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index ef02318..5e983ad 100644
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -2433,7 +2433,7 @@
   //  |-----
   //  v
   // BB
-  BranchInst *PredTerm = dyn_cast<BranchInst>(Pred->getTerminator());
+  BranchInst *PredTerm = cast<BranchInst>(Pred->getTerminator());
   BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), "select.unfold",
                                          BB->getParent(), BB);
   // Move the unconditional branch to NewBB.