RecursivelyDeleteTriviallyDeadInstructions only needs a

Value, not an Instruction, so casting is not necessary. Also,
it's theoretically possible that the Value is not an
Instruction, since WeakVH follows RAUWs.

llvm-svn: 127427

llvm/lib/Transforms/Scalar/Reassociate.cpp

@@ -1097,9 +1097,8 @@ bool Reassociate::runOnFunction(Function &F) {
 
   // Now that we're done, delete any instructions which are no longer used.
   while (!DeadInsts.empty())
-    if (Instruction *Inst =
-          cast_or_null<Instruction>((Value *)DeadInsts.pop_back_val()))
-      RecursivelyDeleteTriviallyDeadInstructions(Inst);
+    if (Value *V = DeadInsts.pop_back_val())
+      RecursivelyDeleteTriviallyDeadInstructions(V);
 
   // We are done with the rank map.
   RankMap.clear();