[libc++] Cleanup and enable multiple warnings.

Too many warnings are being disabled too quickly. Warnings are
important to keeping libc++ correct. This patch re-enables two
warnings: -Wconstant-evaluated and -Wdeprecated-copy.

In future, all warnings disabled for the test suite should require
an attached bug. The bug should state the plan for re-enabling that
warning, or a strong case why it should remain disabled.

1 files changed, 1 insertions, 0 deletions

diff --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
index a5ff10201c9..f14e20657d7 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
@@ -30,6 +30,7 @@ struct X
         if (throw_now)
             TEST_THROW(6);
     }
+    X& operator=(X const&) = default;
 };
 
 bool X::throw_now = false;