[llvm] [RISCV][VLOpt] Minor worklist invariant cleanup [NFC] (PR #123989)

[Michael Maitland via llvm-commits]

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@@ -1388,6 +1386,7 @@ bool RISCVVLOptimizer::runOnMachineFunction(MachineFunction &MF) {
   while (!Worklist.empty()) {
     assert(MadeChange);
     MachineInstr &MI = *Worklist.pop_back_val();
+    assert(isCandidate(MI));
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michaelmaitland wrote:

We can keep it. It is cheap. 

https://github.com/llvm/llvm-project/pull/123989