message: add another LLVM bug found
diff: @@ -75,6 +75,7 @@ Please contact us or submit a PR if something is missing or inaccurate.
  68. SLP vectorizer's reduce_and formation introduces poison (https://llvm.org/PR55734)
  69. IRCE introduces UB by changing order of condition checks (https://llvm.org/PR57523)
  70. LoopIdiomRecognizer creates memset_pattern16 with incorrect size type with custom dl (https://llvm.org/PR57679)
  +71. InstSimplify: xor pattern miscompiles undef lane (https://llvm.org/PR58977)
  ### Bugs found in Z3
  