[llvm] [SLP][REVEC] Make ShuffleCostEstimator and ShuffleInstructionBuilder can vectorize vector instructions. (PR #99606)

[Han-Kuan Chen via llvm-commits]

HanKuanChen wrote:

> Need the tests

This PR and https://github.com/llvm/llvm-project/pull/99499 are trying to solve the same test (test3 in `llvm/test/Transforms/SLPVectorizer/revec.ll`).
Do I need to merge this into https://github.com/llvm/llvm-project/pull/99499?

https://github.com/llvm/llvm-project/pull/99606