Suppress -Waligned-allocation-unavailable warning in libc++ test suite

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@307218 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/libcxx/test/config.py b/utils/libcxx/test/config.py
index 96b3df5..0d5249b 100644
--- a/utils/libcxx/test/config.py
+++ b/utils/libcxx/test/config.py
@@ -888,6 +888,7 @@
         self.cxx.addWarningFlagIfSupported('-Wno-c++11-extensions')
         self.cxx.addWarningFlagIfSupported('-Wno-user-defined-literals')
         self.cxx.addWarningFlagIfSupported('-Wno-noexcept-type')
+        self.cxx.addWarningFlagIfSupported('-Wno-aligned-allocation-unavailable')
         # These warnings should be enabled in order to support the MSVC
         # team using the test suite; They enable the warnings below and
         # expect the test suite to be clean.