Fix tests after allowing imports to clash with keywords

Author: DougGregor

test/1_stdlib/Nil.swift

@@ -25,7 +25,7 @@ if unsafeNil == nil {
 }
 
 do {
-  try NSFileManager.defaultManager().removeItem(at: NSURL(string:"/this/file/does/not/exist")!)
+  try NSFileManager.`default`().removeItem(at: NSURL(string:"/this/file/does/not/exist")!)
 } catch {
   print("ok !removed")
   // CHECK: ok !removed

test/ClangModules/sdk-bridging-header.swift

@@ -16,7 +16,7 @@
 
 import Foundation
 
-let `true` = Predicate.truePredicate()
+let `true` = Predicate.`true`()
 let not = Predicate.not()
 let and = Predicate.and([])
 let or = Predicate.or([not, and])

test/IDE/complete_pound_selector.swift

@@ -21,7 +21,7 @@ import Foundation
 }
 
 func selectorArg1(obj: NSObject) {
-  obj.doSelector(#^SELECTOR_ARG1^#
+  obj.`do`(#^SELECTOR_ARG1^#
 }
 
 func selectorArg2(obj: NSObject) {

test/Interpreter/SDK/Foundation_test.swift

@@ -181,7 +181,7 @@ FoundationTestSuite.test("patternMatching") {
 // Type checker used to crash on this.
 class ClassWithDtor : NSObject {
   deinit {
-    let noteCenter = NSNotificationCenter.defaultCenter()
+    let noteCenter = NSNotificationCenter.`default`()
     noteCenter.removeObserver(self, name: "ReceivedContentNotification", object: nil)
   }
 }

test/Interpreter/SDK/objc_array_of_classes.swift

@@ -11,7 +11,7 @@ var NSURLSessionConfigurationUsage = TestSuite("NSURLSessionConfigurationUsage")
 // NSArray<Class> * in Foundation. Make sure it works.
 NSURLSessionConfigurationUsage.test("protocolClasses") {
   if let protocols = NSURLSessionConfiguration
-    .defaultSessionConfiguration()
+    .`default`()
     .protocolClasses {
 
     for proto in protocols {