[test] Disable some concurrency tests on Windows

https://bugs.swift.org/browse/SR-14333

Author: lorentey

test/Concurrency/Runtime/async_task_detached.swift

@@ -3,8 +3,8 @@
 // REQUIRES: executable_test
 // REQUIRES: concurrency
 
-// See SR-14333
-// UNSUPPORTED: MSVC_VER=15.0
+// https://bugs.swift.org/browse/SR-14333
+// UNSUPPORTED: OS=windows-msvc
 
 class X {
   init() {

test/IRGen/async/throwing.swift

@@ -7,9 +7,8 @@
 // REQUIRES: concurrency
 // UNSUPPORTED: use_os_stdlib
 
-// See SR-14333
-// XFAIL: OS=windows-msvc
-// UNSUPPORTED: MSVC_VER=15.0
+// https://bugs.swift.org/browse/SR-14333
+// UNSUPPORTED: OS=windows-msvc
 
 struct E : Error {}