Fix imports: Remove CoreFoundation and fix Glibc

Author: spevans

TestFoundation/TestCalendar.swift

@@ -14,7 +14,6 @@ import XCTest
 import SwiftFoundation
 import SwiftXCTest
 #endif
-import CoreFoundation
 
 class TestCalendar: XCTestCase {
 

TestFoundation/TestNSGeometry.swift

@@ -11,7 +11,6 @@
 #if DEPLOYMENT_RUNTIME_OBJC || os(Linux)
     import Foundation
     import XCTest
-    import CoreFoundation
 #else
     import SwiftFoundation
     import SwiftXCTest

TestFoundation/TestNumberFormatter.swift

@@ -14,7 +14,6 @@
     import SwiftFoundation
     import SwiftXCTest
 #endif
-import CoreFoundation
 
 class TestNumberFormatter: XCTestCase {
 

TestFoundation/TestProcess.swift

@@ -14,7 +14,6 @@
     import SwiftFoundation
     import SwiftXCTest
 #endif
-import CoreFoundation
 
 class TestProcess : XCTestCase {
     static var allTests: [(String, (TestProcess) -> () throws -> Void)] {

TestFoundation/TestXMLDocument.swift

@@ -17,7 +17,6 @@
     import SwiftXCTest
 #endif
 
-import CoreFoundation
 
 class TestXMLDocument : XCTestCase {
 

TestFoundation/main.swift

@@ -10,13 +10,18 @@
 #if DEPLOYMENT_RUNTIME_OBJC || os(Linux)
 import Foundation
 import XCTest
-import Glibc
 #else
 import SwiftFoundation
 import SwiftXCTest
-import Darwin
 #endif
 
+#if os(OSX) || os(iOS)
+    import Darwin
+#elseif os(Linux)
+    import Glibc
+#endif
+
+
 internal func testBundle() -> Bundle {
     return Bundle.main
 }