[libc++][test][msan] Refine XFAIL after #67799

[vitalybuka]

Undo a part of #73152.

These test do not hang, but unexpectedlty pass on aarch64
https://lab.llvm.org/buildbot/#/builders/74/builds/23708

Tests work on aarch64 and probably any platform without fp80.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Vitaly Buka (vitalybuka)

Changes

Undo a part of #73152.

These test do not hang, but unexpectedlty pass on aarch64
https://lab.llvm.org/buildbot/#/builders/74/builds/23708

Test work on aarch64 and probably any platform without fp80.

---

Full diff: https://github.com/llvm/llvm-project/pull/73213.diff

2 Files Affected:

• (modified) libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/exchange.pass.cpp (+1-2)
• (modified) libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/wait.pass.cpp (+1-2)

diff --git a/libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/exchange.pass.cpp b/libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/exchange.pass.cpp
index 87ce7ab05d92e6c..a8306304280c545 100644
--- a/libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/exchange.pass.cpp
+++ b/libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/exchange.pass.cpp
@@ -9,8 +9,7 @@
 // UNSUPPORTED: target={{.+}}-windows-gnu
 // Clang's support for atomic operations on long double is broken. See https://github.com/llvm/llvm-project/issues/72893
 // XFAIL: tsan
-// Hangs with msan.
-// UNSUPPORTED: msan
+// XFAIL: target={{x86_64-.*}} && msan
 // ADDITIONAL_COMPILE_FLAGS(has-latomic): -latomic
 
 //  T exchange(T, memory_order = memory_order::seq_cst) volatile noexcept;
diff --git a/libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/wait.pass.cpp b/libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/wait.pass.cpp
index e3a8c576ef0167e..15f3613245a836e 100644
--- a/libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/wait.pass.cpp
+++ b/libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/wait.pass.cpp
@@ -9,8 +9,7 @@
 // XFAIL: availability-synchronization_library-missing
 // Clang's support for atomic operations on long double is broken. See https://github.com/llvm/llvm-project/issues/72893
 // XFAIL: tsan
-// Hangs with msan.
-// UNSUPPORTED: msan
+// XFAIL: target={{x86_64-.*}} && msan
 // ADDITIONAL_COMPILE_FLAGS(has-latomic): -latomic
 
 // void wait(T old, memory_order order = memory_order::seq_cst) const volatile noexcept;

[huixie90]

LGTM