[llvm] Delete assignment operator from `MachineBlockFrequencyInfo` (PR #101289)

[Phoebe Wang via llvm-commits]

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@@ -41,6 +41,8 @@ class MachineBlockFrequencyInfo {
                                      MachineBranchProbabilityInfo &MBPI,
                                      MachineLoopInfo &MLI);
   MachineBlockFrequencyInfo(MachineBlockFrequencyInfo &&);
+  MachineBlockFrequencyInfo &
+  operator=(const MachineBlockFrequencyInfo &) = delete;
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phoebewang wrote:

Should we use `= default` like above?

https://github.com/llvm/llvm-project/pull/101289