[llvm] [RISCV] Take known minimum vlen into account when calculating alignment padding in assignRVVStackObjectOffsets. (PR #110312)

[Philip Reames via llvm-commits]

https://github.com/preames approved this pull request.

I think this is correct, but the (existing) pattern of using fixed offsets to represent a combined scalable + fixed term here makes me uncomfortable that I'm understanding it correctly.  I think this code would be much easier to follow if we used TypeSize to the extend we can get away with it through this code.

https://github.com/llvm/llvm-project/pull/110312