Update NSJSONSerialization to new naming
Update NSJSONSerialization to new naming

This needs a synchronized merge with https://github.com/apple/swift-corelibs-foundation/pull/373 @parkera
sschiau/swift-package-manager,haskellswift/swift-package-manager,haskellswift/swift-package-manager,vmanot/swift-package-manager,JGiola/swift-package-manager,sschiau/swift-package-manager,sschiau/swift-package-manager,mxcl/swift-package-manager,vmanot/swift-package-manager,abertelrud/swift-package-manager,vmanot/swift-package-manager,sschiau/swift-package-manager,sschiau/swift-package-manager,apple/swift-package-manager,JGiola/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,apple/swift-package-manager,mxcl/swift-package-manager,JGiola/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,mxcl/swift-package-manager,JGiola/swift-package-manager,JGiola/swift-package-manager,vmanot/swift-package-manager,abertelrud/swift-package-manager,haskellswift/swift-package-manager,haskellswift/swift-package-manager,mxcl/swift-package-manager,vmanot/swift-package-manager,abertelrud/swift-package-manager