add missing preserves CFG

Author: optimisan

llvm/lib/CodeGen/RegisterCoalescer.cpp

@@ -4252,6 +4252,7 @@ RegisterCoalescerPass::run(MachineFunction &MF,
   if (!Impl.run(MF))
     return PreservedAnalyses::all();
   auto PA = getMachineFunctionPassPreservedAnalyses();
+  PA.preserveSet<CFGAnalyses>();
   PA.preserve<LiveIntervalsAnalysis>();
   PA.preserve<SlotIndexesAnalysis>();
   PA.preserve<MachineLoopAnalysis>();