[llvm] [X86] Try Folding icmp of v8i32 -> fcmp of v8f32 on AVX (PR #82290)

[via llvm-commits]

goldsteinn wrote:

> I'm not sure about the OkayBitcast codepath - I was just expecting some simple knownbits min/max value tests and SINT_TO_FP calls that would also handle constant folding.

Whats wrong with the `bitcast` codepath? Its just the same idea as the `SINT_TO_FP` one but saves an instruction.

https://github.com/llvm/llvm-project/pull/82290