Identify BCP 47 identifiers and turn them into Locale objects

[zadr]

BCP 47 defines Tags for Identifying Languages.

Given the following JSON:

{
    "language": "en",
    "foo": true
}

j2s will currently output the following Swift code:

public struct Root {
	let foo: Bool
	let language: String

	init?(_ dictionary: [String: Any]) {
		if let foo = dictionary["foo"] as? Bool {
			self.foo = foo
		} else {
			return nil
		}
		
		if let language = dictionary["language"] as? String {
			self.language = language
		} else {
			return nil
		}
	}
}

but it might be useful if could identify BCP 47 identifiers and instead output code using Locales, such as:

public struct Root {
	let foo: Bool
	let language: String

	init?(_ dictionary: [String: Any]) {
		if let foo = dictionary["foo"] as? Bool {
			self.foo = foo
		} else {
			return nil
		}
		
		if let language = dictionary["language"] as? String {
			Locale(localeIdentifier: language)
		} else {
			return nil
		}
	}
}

[zadr]

fixed by f0d5fa5

[zadr]

this was un-fixed after starting to generate Codable-compliant code