[llvm] [SLP] Bail out on store-to-load forwarding hazards (PR #199606)

[Milin Bhade via llvm-commits]

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mbhade-amd wrote:

It's conservative, not load-bearing. An interleaved store is still a contiguous <VF x T> store (only lanes are shuffled), and it can't trip the check anyway: its values come from forward loads, so its tree never holds the widened backward load a hazard needs. I'll drop the guard. 

https://github.com/llvm/llvm-project/pull/199606