[llvm] [HEXAGON] [MachinePipeliner] Fix the DAG in case of dependent phis. (PR #135925)

[Ryotaro Kasuga via llvm-commits]

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@@ -5,11 +5,13 @@
 ; 2, so the computation for the number of Phis needs to be adjusted when
 ; the incoming prolog block is from prolog 0 or prolog 1.
 ; Note: the pipeliner no longer generates a 3 stage pipeline for this test.
+; Note: the pipeliner has been generating a 4-stage pipelined loop.
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kasuga-fj wrote:

I think the comment one line above is wrong and can be deleted.

https://github.com/llvm/llvm-project/pull/135925