Consistently import _CFXMLInterface

Author: parkera

Sources/FoundationXML/XMLNode.swift

@@ -10,7 +10,7 @@
 //import libxml2
 #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
 import SwiftFoundation
-import _CFXMLInterface
+@_implementationOnly import _CFXMLInterface
 #else
 import Foundation
 @_implementationOnly import _CFXMLInterface

Sources/FoundationXML/XMLParser.swift

@@ -9,7 +9,7 @@
 
 #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
 import SwiftFoundation
-import _CFXMLInterface
+@_implementationOnly import _CFXMLInterface
 #else
 import Foundation
 @_implementationOnly import _CFXMLInterface