[stdlib] Remove documentation piece that it is not longer true.

[drodriguez]

Since a4e9109 (#17396), both the hashes and the equality of numeric
types inside of AnyHashable do not follow the rules that this part of
the comment was talking about.

I couldn't find an easy example that shows the same behaviour, so I
decided to remove the comment completely.

/cc @lorentey

[lorentey]

One way to demonstrate the behavior is to use a custom wrapper struct as one of the types:

struct Wrapper: Hashable {
  let value: Int
}

let x = AnyHashable(Int(42))		
let y = AnyHashable(Wrapper(value: 42))		

print(x == y)		
// Prints "false" because `Int` and `Wrapper` are different types		

print(x == AnyHashable(Int(42)))		
// Prints "true"

[lorentey]

I'd be fine with either removing the example or updating it -- @natecook1000, what do you think?

[drodriguez]

I think the interesting part of the previous example was that even if Int(42) == UInt8(42), the type-erased values do not compare the same. With the changes which keep the equality properties of the underlaying values, that little disagreement is not longer true.

In my opinion, the proposed example doesn't work in the same way, since the equality between Wrapper and Int will never be true.

[natecook1000]

There are a couple funky things intersecting here: (1) we have heterogeneous equality operators defined for integers, and (2) AnyHashable uses NSNumber semantics for comparison, even when Foundation hasn't been imported. You can see this by comparing AnyHash'd integer and floating-point values:

let x = AnyHashable(Int(42))
let y = AnyHashable(Double(42))

x == y // true

Whereas you couldn't compare an Int and Double that weren't wrapped.

All that said, I think it makes sense to take these examples out and note the oddity in the type overview. Thanks for looking at this, @drodriguez!

[natecook1000]

@swift-ci Please smoke test and merge

[drodriguez]

@swift-ci please smoke test and merge

[drodriguez]

Trying again if my CI powers have been enabled. In any case, the macOS failure seems to be unrelated to the changes. If my request to CI doesn’t work, would someone start it up for me? Thanks!

[compnerd]

@swift-ci please test macOS platform