[SR-2228] Unhelpful error message for lack of label in `String.init(describing:)`

[xwu]

Previous ID	SR-2228
Radar	None
Original Reporter	@xwu
Type	Bug
Status	Resolved
Resolution	Done

Additional Detail from JIRA

Votes	0
Component/s	Compiler, Standard Library
Labels	Bug, DiagnosticsQoI
Assignee	@harlanhaskins
Priority	Medium

md5: e65357ba7b425d2f6a0f8b634b7197a0

Issue Description:

After implementation of `LosslessStringConvertible`, non-lossless string conversions require the argument label `describing`. However, this is not what the errors tell you. For example, in a Playground, write:

```
let bar = [1 as Float, 2, 3]
String(bar[0..<2]) // error: ambiguous reference to member '..<'
```

And if you write instead:

```
let bar = [1 as Float, 2, 3]
let baz = String(bar[0..<2]) // error: type of expression is ambiguous without more context
```

[belkadan]

This is probably important enough to either see if we can add the old overload and mark it unavailable, or to come up with a hardcoded special-case diagnostic in the compiler. CodaFi (JIRA User), @dabrahams, what do you think?

[CodaFi]

Does overload resolution fire for `Any` before `T`? If so, I think it's doable.

[dabrahams]

This should be easy. Yes, I agree that it should be done.

[CodaFi]

Resolved in #3962