float types: document NaN bit pattern guarantees Part of https://github.com/rust-lang/rust/issues/128288: document the guarantees we make for NaN bit patterns. Cc ``@tgross35``
float types: document NaN bit pattern guarantees Part of https://github.com/rust-lang/rust/issues/128288: document the guarantees we make for NaN bit patterns. Cc ``@tgross35``