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

llvm-svn: 283978
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: fc647db3ee8215ab2fa5f7cdea8d327c2faa768f
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