[MemoryTaggingSupport] Remove unnecessary bitcast (NFC)

As the comment indicates, this is no longer necessary with
opaque pointers.

Author: nikic

llvm/lib/Transforms/Utils/MemoryTaggingSupport.cpp

@@ -232,13 +232,7 @@ void alignAndPadAlloca(memtag::AllocaInfo &Info, llvm::Align Alignment) {
   NewAI->setSwiftError(Info.AI->isSwiftError());
   NewAI->copyMetadata(*Info.AI);
 
-  Value *NewPtr = NewAI;
-
-  // TODO: Remove when typed pointers dropped
-  if (Info.AI->getType() != NewAI->getType())
-    NewPtr = new BitCastInst(NewAI, Info.AI->getType(), "", Info.AI->getIterator());
-
-  Info.AI->replaceAllUsesWith(NewPtr);
+  Info.AI->replaceAllUsesWith(NewAI);
   Info.AI->eraseFromParent();
   Info.AI = NewAI;
 }