[libcxx] [www] Semi-manually change http://www.open-std.org and http://isocpp.org papers to https://wg21.link .

Fixes D37318.

llvm-svn: 312259
diff --git a/libcxx/www/atomic_design_c.html b/libcxx/www/atomic_design_c.html
index b431917..ea23fb8 100644
--- a/libcxx/www/atomic_design_c.html
+++ b/libcxx/www/atomic_design_c.html
@@ -328,7 +328,7 @@
 
 <p>
 One should consult the (currently draft)
-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf">C++ standard</a>
+<a href="https://wg21.link/n3126">C++ standard</a>
 for the details of the definitions for these operations.  For example
 <tt>__atomic_compare_exchange_weak_seq_cst_seq_cst</tt> is allowed to fail
 spuriously while <tt>__atomic_compare_exchange_strong_seq_cst_seq_cst</tt> is
@@ -370,7 +370,7 @@
 
 <p>
 (See the
-<a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf">C++ standard</a>
+<a href="https://wg21.link/n3126">C++ standard</a>
 for the detailed definitions of each of these orderings).
 </p>