Add libc++ and libc++abi to third-party.

third_party/libc++/src/valarray.cpp

+//===------------------------ valarray.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.
+//
+//===----------------------------------------------------------------------===//
+
+#define _LIBCPP_EXTERN_TEMPLATE(...) extern template __VA_ARGS__;
+
+#include "valarray"
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template valarray<size_t>::valarray(size_t);
+template valarray<size_t>::~valarray();
+template void valarray<size_t>::resize(size_t, size_t);
+
+void
+gslice::__init(size_t __start)
+{
+    valarray<size_t> __indices(__size_.size());
+    size_t __k = __size_.size() != 0;
+    for (size_t __i = 0; __i < __size_.size(); ++__i)
+        __k *= __size_[__i];
+    __1d_.resize(__k);
+    if (__1d_.size())
+    {
+        __k = 0;
+        __1d_[__k] = __start;
+        while (true)
+        {
+            size_t __i = __indices.size() - 1;
+            while (true)
+            {
+                if (++__indices[__i] < __size_[__i])
+                {
+                    ++__k;
+                    __1d_[__k] = __1d_[__k-1] + __stride_[__i];
+                    for (size_t __j = __i + 1; __j != __indices.size(); ++__j)
+                        __1d_[__k] -= __stride_[__j] * (__size_[__j] - 1);
+                    break;
+                }
+                else
+                {
+                    if (__i == 0)
+                        return;
+                    __indices[__i--] = 0;
+                }
+            }
+        }
+    }
+}
+
+_LIBCPP_END_NAMESPACE_STD