[libcxx] [test] Convert an XFAIL: LIBCXX-WINDOWS-FIXME into XFAIL: msvc

[mstorsjo]

Summary

This one already had a proper explanation why it fails, which is due to
differences by design in MSVC mode. This isn't a fixme, so degrade the
annotation to a more permanent "XFAIL: msvc" instead.

[• Quuxplusone]

libcxx/test/libcxx/atomics/diagnose_invalid_memory_order.verify.cpp

9–13

Should msvc simply undefine diagnose-if-support?
Right now we don't have many tests that check either of these flags:

$ git grep msvc
std/input.output/iostreams.base/ios.base/ios.base.storage/iword.pass.cpp:// UNSUPPORTED: msvc
std/input.output/iostreams.base/ios.base/ios.base.storage/pword.pass.cpp:// UNSUPPORTED: msvc
std/language.support/cmp/cmp.categories.pre/zero_type.verify.cpp:// UNSUPPORTED: msvc
std/thread/thread.mutex/thread.lock.algorithm/lock.pass.cpp:// UNSUPPORTED: libstdc++, msvc
std/utilities/meta/meta.trans/meta.trans.other/underlying_type.fail.cpp:// UNSUPPORTED: msvc

$ git grep diagnose-if-support
libcxx/atomics/diagnose_invalid_memory_order.verify.cpp:// REQUIRES: diagnose-if-support
libcxx/containers/associative/non_const_comparator.verify.cpp:// REQUIRES: diagnose-if-support
libcxx/containers/unord/non_const_comparator.verify.cpp:// REQUIRES: diagnose-if-support
libcxx/containers/unord/unord.set/missing_hash_specialization.fail.cpp:// REQUIRES: diagnose-if-support

[mstorsjo]

libcxx/test/libcxx/atomics/diagnose_invalid_memory_order.verify.cpp

9–13

I don't see the value in doing that - out of those 4 REQUIRES: diagnose-if-support, this is the only one that has problems running with MSVC configurations.

And the fact that we only have a handful of tests that check the msvc flag doesn't mean it that flag should be discontinued - we right now still have 66 unsorted LIBXX-WINDOWS-FIXME - out of them, 10 still seem to be MSVC specific that might warrant changing into UNSUPPORTED/XFAIL: msvc or something like that, after analyzing their root causes.

libcxx/test/libcxx/atomics/diagnose_invalid_memory_order.verify.cpp

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 // This test fails because diagnose_if doesn't emit all of the diagnostics
-// when -fdelayed-template-parsing is enabled, like it is on Windows.
-// XFAIL: LIBCXX-WINDOWS-FIXME
+// when -fdelayed-template-parsing is enabled, like it is in MSVC mode.
+// XFAIL: msvc
 
 // REQUIRES: diagnose-if-support
 // UNSUPPORTED: libcpp-has-no-threads
 
 // <atomic>
 
 // Test that invalid memory order arguments are diagnosed where possible.
 
 #include <atomic>