Just disable the GameplayKit test and do not link against GameplayKit everywhere.

Looks like there is a discrepency in between the public/private SDK with the
safety of just including GameplayKit everywhere.

rdar://23527707

test/lit.cfg

@@ -559,7 +559,7 @@ if run_vendor == 'apple':
         config.target_cc_options = target_cc_options
         extra_frameworks = ['AppKit', 'CoreGraphics', 'SceneKit', 'CoreLocation',
                             'Accelerate', 'CoreImage', 'QuartzCore', 'CoreMedia',
-                            'OpenCL', 'GameplayKit']
+                            'OpenCL']
         config.target_build_swift = (
             "%s %s %s -F %s -Xlinker -rpath -Xlinker %s %s %s %s %s"
             % (xcrun_prefix, config.swiftc, target_options,

validation-test/stdlib/GameplayKit.swift

@@ -3,6 +3,7 @@
 
 // REQUIRES: objc_interop
 // UNSUPPORTED: OS=watchos
+// REQUIRES: rdar23527707
 
 import StdlibUnittest
 import GameplayKit