Update comment

Author: arsenm

llvm/lib/Transforms/InstCombine/InstructionCombining.cpp

@@ -3656,7 +3656,7 @@ Instruction *InstCombinerImpl::visitUnconditionalBranchInst(BranchInst &BI) {
   assert(BI.isUnconditional() && "Only for unconditional branches.");
 
   // If this store is the second-to-last instruction in the basic block
-  // (excluding debug info and bitcasts of pointers) and if the block ends with
+  // (excluding debug info) and if the block ends with
   // an unconditional branch, try to move the store to the successor block.
 
   auto GetLastSinkableStore = [](BasicBlock::iterator BBI) {