Support for Swift language and Clang modules for ninja generator.

test/ios/swift/MySwiftClass.swift

+import Foundation
+import swift_framework
+
+public class MySwiftClass : NSObject {
+  public override init() {
+    objcField = MyObjcClass()
+    swiftField = MySecondSwiftClass()
+    frameworkSwiftField = MySwiftFrameworkClass()
+    frameworkObjcField = MyObjcFrameworkClass()
+  }
+  public var intField: Int = 0
+  var objcField: MyObjcClass
+  var swiftField: MySecondSwiftClass
+  var frameworkSwiftField: MySwiftFrameworkClass
+  var frameworkObjcField: MyObjcFrameworkClass
+}