Cranelift interpreter does not respect nan canonicalization setting

This test:

```
test interpret
test run
set enable_nan_canonicalization=true
target x86_64

function %a(f32) -> f32 system_v {
block0(v0: f32):
v1 = floor v0
return v1
}

; run: %a(-sNaN:0x2f20ff) == -sNaN:0x2f20ff
```

"passes" in the interpreter but "fails" on native. Native produces the result `+NaN` which is the correct result of this function due to the `enable_nan_canonicalization` flag being enabled.

Currently the interpreter, neither with `test interpret` nor during fuzzing, does not respect NaN canonicalization meaning it's producing false positives in differential fuzzing.