Code cleanup: Remove std::move() around xvalue (NFC)

Remove std::move() around xvalue so that copy elision is eligible.
In case that copy elision is not appliable, the c++ standard also
guarantees the move semantics on xvalue.  Thus, it is not necessary
to wrap Args with std::move.

This also silence a warning since r240345.

llvm-svn: 240355

lib/Option/OptTable.cpp

@@ -287,7 +287,7 @@ InputArgList OptTable::ParseArgs(ArrayRef<const char *> ArgArr,
     Args.append(A);
   }
 
-  return std::move(Args);
+  return Args;
 }
 
 static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {