[llvm] [LV] Enable considering higher VFs when data extend ops are present i… (PR #137593)

[David Sherwood via llvm-commits]

david-arm wrote:

> shouldMaximizeVectorBandwidth

I agree. I think the correct place to do this would be in `shouldMaximizeVectorBandwidth`, since not all targets want to maximise the bandwidth. Enabling this by default has been observed may lead to performance regressions.

https://github.com/llvm/llvm-project/pull/137593