Disable XCTest.swift until bot is upgraded.

gottesmm · gottesmm · commit bddea630d934 · 2016-05-13T22:04:40.000-07:00
(cherry picked from commit b617d6b)
diff --git a/validation-test/stdlib/XCTest.swift b/validation-test/stdlib/XCTest.swift
@@ -4,6 +4,7 @@
 // REQUIRES: objc_interop
 
 // REQUIRES: OS=macosx
+// REQUIRES: disabled
 
 // watchOS 2.0 does not have an XCTest module.
 // XFAIL: OS=watchos
