[llvm] [VPlan] Use pointer to member 0 as VPInterleaveRecipe's pointer arg. (PR #106431)

[Florian Hahn via llvm-commits]

fhahn wrote:

@alexhf thanks! Should be fixed in bbff5b8891c0ce929d6. The issue was that the patch was using `getScalarSizeInBits`, which returned 0 for pointers. Fixed by using getAllocTypeSize (in line with what the interleave analysis uses)

https://github.com/llvm/llvm-project/pull/106431