[LVI] Remove support for SPF selects

[nikic]

No description provided.

[dtcxzyw]

I tried to remove the SPF support in LVI after #76630. But it seems to cause regression:
https://dtcxzyw.github.io/llvm-opt-benchmark/coverage/data/zyw/opt-ci/actions-runner/_work/llvm-opt-benchmark/llvm-opt-benchmark/llvm/llvm-project/llvm/lib/Analysis/LazyValueInfo.cpp.html#L807

[nikic]

@dtcxzyw The first CVP run is before the first InstCombine run in the function simplification pipeline, so it's kind of expected. Usually it should be recovered later, but there are indeed some minor regressions in the diff.

[nikic]

Not pursuing this right now.