Eliminate some deep std::vector copies. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218999 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/IPO/ArgumentPromotion.cpp

@@ -530,7 +530,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg,
         // of elements of the aggregate.
         return false;
       }
-      ToPromote.insert(Operands);
+      ToPromote.insert(std::move(Operands));
     }
   }