[llvm] [VectorCombine] Fix duplicate freeze scheduling for shared indexes (PR #213461)

[Aditya prakash jha via llvm-commits]

AdityaOP007 wrote:

@ParkHanbum I've updated the PR based on your feedback: freeze tracking now uses the shared index instruction, the unrelated IdxBase changes have been removed, and the regression test now uses the extract results to exercise the shared-index case. I also removed the temporary test files. Please take another look when you get a chance.

https://github.com/llvm/llvm-project/pull/213461