[test] Only running the test on watchOS simulator (#7801)

<rdar://problem/29996841>

Author: moiseev

test/stdlib/DispatchDeprecationWatchOS.swift

@@ -1,5 +1,5 @@
 // RUN: %swift -typecheck -target i386-apple-watchos2.0 -verify -sdk %sdk %s
-// REQUIRES: OS=watchos
+// REQUIRES: CPU=i386, OS=watchos
 // REQUIRES: objc_interop
 
 import Foundation