[llvm][IRMover] Remove no-op ptr-to-ptr bitcast (NFC)

Opaque ptr cleanup effort.

Author: JOE1994

llvm/lib/Linker/IRMover.cpp

@@ -989,8 +989,7 @@ IRLinker::linkAppendingVarProto(GlobalVariable *DstGV,
   // Replace any uses of the two global variables with uses of the new
   // global.
   if (DstGV) {
-    RAUWWorklist.push_back(
-        std::make_pair(DstGV, ConstantExpr::getBitCast(NG, DstGV->getType())));
+    RAUWWorklist.push_back(std::make_pair(DstGV, NG));
   }
 
   return Ret;