Add #self, #Self to #function, #file, #line, #column

Evolution Pitches
27

Could #Self / #type be implemented as a macro? I gave it a try but my macro-fu needs improvements.

Macro attempt that doesn't work 
public struct TypeNameMacro: ExpressionMacro {
    public static func expansion(of node: some FreestandingMacroExpansionSyntax, in context: some MacroExpansionContext) throws -> ExprSyntax {
        var currentNode: Syntax? = Syntax(node)

        while let node = currentNode {
            if let structDecl = node.as(StructDeclSyntax.self) {
                return ExprSyntax(StringLiteralExprSyntax(content: structDecl.name.text))
            }
            if let classDecl = node.as(ClassDeclSyntax.self) {
                return ExprSyntax(StringLiteralExprSyntax(content: classDecl.name.text))
            }
            if let enumDecl = node.as(EnumDeclSyntax.self) {
                return ExprSyntax(StringLiteralExprSyntax(content: enumDecl.name.text))
            }
            currentNode = node.parent
        }
        return ExprSyntax(StringLiteralExprSyntax(content: "<global>"))
    }
}