[RISCV] Manage the InQueue flag in insertvli correctly.

[craig.topper]

Summary

We were only setting this flag the first time we added the blocks
not when we mark them for revisiting.

[reames]

LGTM

llvm/lib/Target/RISCV/RISCVInsertVSETVLI.cpp

void RISCVInsertVSETVLI::computeIncomingVLVTYPE(const MachineBasicBlock &MBB) {
 
   BBInfo.Exit = TmpStatus;
   LLVM_DEBUG(dbgs() << "Exit state of " << printMBBReference(MBB)
                     << " changed to " << BBInfo.Exit << "\n");
 
   // Add the successors to the work list so we can propagate the changed exit
   // status.
   for (MachineBasicBlock *S : MBB.successors())
-    if (!BlockInfo[S->getNumber()].InQueue)
+    if (!BlockInfo[S->getNumber()].InQueue) {
+      BlockInfo[S->getNumber()].InQueue = true;
       WorkList.push(S);
     }
+}
 
 // If we weren't able to prove a vsetvli was directly unneeded, it might still
 // be unneeded if the AVL is a phi node where all incoming values are VL
 // outputs from the last VSETVLI in their respective basic blocks.
 bool RISCVInsertVSETVLI::needVSETVLIPHI(const VSETVLIInfo &Require,
                                         const MachineBasicBlock &MBB) const {
   if (DisableInsertVSETVLPHIOpt)
     return true;