Revert Add <optional>. Will recommit with better commit message

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@283978 91177308-0d34-0410-b5e6-96231b3b80d8

src/optional.cpp

diff --git a/src/optional.cpp b/src/optional.cpp
index f2fbfdf..8c5dd76 100644
--- a/src/optional.cpp
+++ b/src/optional.cpp
@@ -7,18 +7,18 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "optional"
 #include "experimental/optional"
 
-namespace std
-{
-
-bad_optional_access::~bad_optional_access() _NOEXCEPT = default;
-
-} // std
-
 _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL
 
+#ifdef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
+
+bad_optional_access::~bad_optional_access() _NOEXCEPT {}
+
+#else
+
 bad_optional_access::~bad_optional_access() _NOEXCEPT = default;
 
+#endif
+
 _LIBCPP_END_NAMESPACE_EXPERIMENTAL