[llvm] [TailDuplicator] Add a limit on the size of predecessors (PR #78582)

[via llvm-commits]

weiguozhi wrote:

If you want to limit the number of tail duplication, I want to see a partial tail duplication base on profile information, similar to MachineBlockPlacement::maybeTailDuplicateBlock.

https://github.com/llvm/llvm-project/pull/78582