[llvm] [AMDGPU] Mark `SI_WATERFALL_LOOP` as divergent in `hasDivergentBranch` (PR #218969)

[Igor Wodiany via llvm-commits]

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@@ -189,3 +189,54 @@ body: |
     FLAT_STORE_DWORD %3, %11, 0, 0, implicit $exec, implicit $flat_scr :: (store (s32))
     SI_RETURN
 ...
+
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IgWod wrote:

See https://github.com/llvm/llvm-project/pull/219171.

https://github.com/llvm/llvm-project/pull/218969