ABI: Fix for undefined "___cxa_deleted_virtual" symbol in MacOSX

Patch from Eddie Elizondo. Reviewed as D37830 (https://reviews.llvm.org/D37830).

On MacOSX the following program:

struct S { virtual void f() = delete; };
int main() { new S; }
Fails with the following error:

Undefined symbols for architecture x86_64:
  "___cxa_deleted_virtual"
This adds a fix to export the needed symbols.

Test:

> lit -sv test/libcxx/language.support/cxa_deleted_virtual.pass.cpp
> Testing Time: 0.21s
>   Expected Passes    : 1



git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@313500 91177308-0d34-0410-b5e6-96231b3b80d8

test/libcxx/language.support/cxa_deleted_virtual.pass.cpp

@@ -0,0 +1,15 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+// Test exporting the symbol: "__cxa_deleted_virtual" in macosx
+
+struct S { virtual void f() = delete; };
+int main() { new S; }