[llvm] [LowerSwitch] Don't let pass manager handle the dependency (PR #68662)

[Jay Foad via llvm-commits]

================
@@ -2076,3 +2076,11 @@ void llvm::InvertBranch(BranchInst *PBI, IRBuilderBase &Builder) {
   PBI->setCondition(NewCond);
   PBI->swapSuccessors();
 }
+
+bool llvm::hasOnlySimpleTerminator(const BasicBlock *BB) {
+  auto *Term = BB->getTerminator();
+  if (isa<ReturnInst>(Term) || isa<UnreachableInst>(Term) ||
+      isa<BranchInst>(Term))
+    return true;
+  return false;
----------------
jayfoad wrote:

```suggestion
  return isa<ReturnInst>(Term) || isa<UnreachableInst>(Term) ||
      isa<BranchInst>(Term);
```

https://github.com/llvm/llvm-project/pull/68662