xcodebuildで使えるSDKのリストを表示する

Xcodeをバージョンアップして、コマンドラインでビルドするときに指定するSDKがわからなくなったら、
以下のコマンドで調べられます。

$ xcodebuild -version -sdk

MacOSX10.9.sdk - OS X 10.9 (macosx10.9)
SDKVersion: 10.9
Path: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk
PlatformVersion: 1.1
PlatformPath: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform
ProductBuildVersion: 13F26
ProductCopyright: 1983-2014 Apple Inc.
ProductName: Mac OS X
ProductUserVisibleVersion: 10.9.5
ProductVersion: 10.9.5

iPhoneOS8.0.sdk - iOS 8.0 (iphoneos8.0)
SDKVersion: 8.0
Path: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS8.0.sdk
PlatformVersion: 8.0
PlatformPath: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform
ProductBuildVersion: 12A365
ProductCopyright: 1983-2014 Apple Inc.
ProductName: iPhone OS
ProductVersion: 8.0

iPhoneSimulator8.0.sdk - Simulator - iOS 8.0 (iphonesimulator8.0)
SDKVersion: 8.0
Path: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.0.sdk
PlatformVersion: 8.0
PlatformPath: /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform
ProductBuildVersion: 12A365
ProductCopyright: 1983-2014 Apple Inc.
ProductName: iPhone OS
ProductVersion: 8.0

Xcode 6.0.1
Build version 6A317