[llvm] Revert "[SLP]Support revectorization of the previously vectorized scalars" (PR #134604)

[Alexey Bataev via llvm-commits]

alexey-bataev wrote:

> This breaks Transforms/SLPVectorizer/X86/reordered-masked-loads.ll. Apparently, the test relies on some changes in #133091.

Will you wait for the fix then? Will try to land it soon

https://github.com/llvm/llvm-project/pull/134604