[C++11] Switch all uses of the llvm_move macro to use std::move
directly, and remove the macro.

llvm-svn: 202612
diff --git a/llvm/utils/yaml-bench/YAMLBench.cpp b/llvm/utils/yaml-bench/YAMLBench.cpp
index f335605..f20a4cc 100644
--- a/llvm/utils/yaml-bench/YAMLBench.cpp
+++ b/llvm/utils/yaml-bench/YAMLBench.cpp
@@ -69,7 +69,7 @@
   if (StringRef(Tag).startswith("tag:yaml.org,2002:")) {
     std::string Ret = "!!";
     Ret += StringRef(Tag).substr(18);
-    return llvm_move(Ret);
+    return std::move(Ret);
   }
   std::string Ret = "!<";
   Ret += Tag;