Revert "Replace expression in ClosureCaptureSyntax with initializer clause"

[rintaro]

Reverts #2763

func test(expr: some ExprSyntaxProtocol) {
  _ = ClosureCaptureSyntax(expression: expr)
}

became ambiguous by this.

[ahoppen]

CC @MAJKFL Could you check why Rintaro’s example is ambiguous and how we can disambiguate it, eg. by adding @_disfavoredOverload to some declaration?

[MAJKFL]

It's ambiguous because we have two deprecated initializers: one with assignToken and the other with equal and both are marked with @_disfavoredOverload. I think the easiest way to fix this would be to remove @_disfavoredOverload from one of them (I think from the one with equal parameter, as it's the most recent one). Should I open a PR?

[ahoppen]

I think the easiest way to fix this would be to remove @_disfavoredOverload from one of them (I think from the one with equal parameter, as it's the most recent one). Should I open a PR?

I think we need the @ _disfavoredOverload for some other ambiguity resolution. Let’s just remove the deprecated initializer with assignToken. That one has been deprecated since 509 (ie. for a year), so I don’t expect that many people still use it. If you could open a PR for that, that would be great!

[MAJKFL]

Ok, I've created #2795 without the initializer and sorry for causing the trouble.

[rintaro]

I don't think we need @ _disfavoredOverload for the equal: one because any other initializers don't accept equal: but I'm not 100% sure. Alternatively we could remove = nil from assignToken: TokenSyntax? = nil so it's resolved only when users call it with an explicit assignToken: argument.

But I'm totally fine with just removing the old deprecated one 👍