Merge 2017-11 LWG Motion 10

Author: zygoloid

source/algorithms.tex

@@ -1376,9 +1376,9 @@
 std::atomic<int> x{0};
 int a[] = {1,2};
 std::for_each(std::execution::par, std::begin(a), std::end(a), [&](int) {
-  x.fetch_add(1, std::memory_order_relaxed);
+  x.fetch_add(1, std::memory_order::relaxed);
   // spin wait for another iteration to change the value of \tcode{x}
-  while (x.load(std::memory_order_relaxed) == 1) { } // incorrect: assumes execution order
+  while (x.load(std::memory_order::relaxed) == 1) { } // incorrect: assumes execution order
 });
 \end{codeblock}
 The above example depends on the order of execution of the iterations, and