[SR-12450] NSString is not LosslessStringConvertible on Linux

[swift-ci]

Previous ID	SR-12450
Radar	rdar://problem/62201058
Original Reporter	rexmas (JIRA User)
Type	Bug
Status	Resolved
Resolution	Done

Environment

Ubuntu 18.04

Swift 5.2

Additional Detail from JIRA

Votes	0
Component/s	Foundation
Labels	Bug
Assignee	@spevans
Priority	Medium

md5: d5d6e088238b0c54331564ba18cc19ea

Issue Description:

NSString is not LosslessStringConvertible on Linux:

$ cat NSTest.swift
import Foundation
let nss = "a" as NSString
print(nss)
print(String(nss))

$ swift NSTest.swift 
NSTest.swift:5:7: error: initializer 'init(_:)' requires that 'NSString' conform to 'LosslessStringConvertible'
print(String(nss))
      ^
Swift.String:4:23: note: where 'T' = 'NSString'
    @inlinable public init<T>(_ value: T) where T : LosslessStringConvertible 

Doing the same test from MacOS prints fine:

$ swift NSTest.swift 
a
a 

[beccadax]

@swift-ci create

[spevans]

This actually looks to be a missing initialiser, the message

error: initializer 'init(_:)' requires that 'NSString' conform to 'LosslessStringConvertible'

seems to be incorrect.

#2813