Feature idea/request: clamp and signum

[torokati44]

They came up in an algorithm I'm considering for SIMDification (ruffle-rs/h263-rs#49), and perhaps they would came in handy for others as well - they are in f32 at least, after all...
I have zero clue though, whether there are intrinsics for these in any platforms... (At least clamp can be done with min and max of course. EDIT: Come to think of it, signum is also just (x > 0) - (x < 0).)

[Lokathor]

These should be pretty easy to add! I'd be happy to merge a PR if you did one.

As you say, they don't need to be specific intrinsics (though that would help), just making them from smaller parts that already exist should work.

[torokati44]

Unfortunately I don't think I have the capacity for a proper PR about this, sorry. :/
I'll leave the issue open in case someone picks it up later.