Make all floating-point operations without precision guarantees non-deterministic

[RalfJung]

With rust-lang/rust#138062, all the floating-point intrinsics are made non-deterministic. However, there are plenty of more floating-point shims that are imported by libstd as regular functions rather than intrinsics; those still need the same treatment.

@LorrensP-2158466 IIRC you said you had a list of these, and you'd be interested in working on this?

[RalfJung]

Oops, we already have this at #3555.

[LorrensP-2158466]

Yes, I'd like to finish my work. I'll post the list in #3555.