[llvm] [RISCV] Check for null LIS before trying to move AVL in canMutatePriorConfig. (PR #196673)

[Pengcheng Wang via llvm-commits]

================
@@ -776,6 +776,10 @@ bool RISCVInsertVSETVLI::canMutatePriorConfig(
       VNInfo *VNI = getVNInfoFromReg(AVL.getReg(), MI, LIS);
       VNInfo *PrevVNI = getVNInfoFromReg(AVL.getReg(), PrevMI, LIS);
       if (!VNI || !PrevVNI || VNI != PrevVNI) {
+        // If LIS is null we were able to get the VNInfo so we don't know if the
----------------
wangpc-pp wrote:

we were able to -> we are not able to?

https://github.com/llvm/llvm-project/pull/196673