Fixes for LWG 2598, 2686, 2739, 2742, 2747, and 2759, which were adopted last week in Issaquah

llvm-svn: 286858
diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 3bafd3df..c5a5d0a 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -877,7 +877,7 @@
 {
     for (; __first != __last; ++__first)
         __f(*__first);
-    return _LIBCPP_EXPLICIT_MOVE(__f);  // explicitly moved for (emulated) C++03
+    return __f;
 }
 
 // find