[libcxx] Add <experimental/any> v2.

Summary:
This patch adds the second revision of <experimental/any>. 
I've been working from the LFTS draft found at this link. https://rawgit.com/cplusplus/fundamentals-ts/v1/fundamentals-ts.html#any



Reviewers: danalbert, jroelofs, K-ballo, mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D6762

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@243728 91177308-0d34-0410-b5e6-96231b3b80d8

src/any.cpp

@@ -0,0 +1,22 @@
+//===---------------------------- any.cpp ---------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "experimental/any"
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS
+
+bad_any_cast::bad_any_cast() _NOEXCEPT {}
+
+bad_any_cast::~bad_any_cast() _NOEXCEPT {}
+
+const char* bad_any_cast::what() const _NOEXCEPT {
+    return "bad any cast";
+}
+
+_LIBCPP_END_NAMESPACE_LFTS