make "names" internal generic

com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/base/Names.java

@@ -23,6 +23,7 @@
 package com.oracle.truffle.r.nodes.builtin.base;
 
 import static com.oracle.truffle.r.runtime.RBuiltinKind.PRIMITIVE;
+import static com.oracle.truffle.r.runtime.RDispatch.INTERNAL_GENERIC;
 
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
 import com.oracle.truffle.api.dsl.Fallback;
@@ -35,7 +36,7 @@ import com.oracle.truffle.r.runtime.data.RNull;
 import com.oracle.truffle.r.runtime.data.model.RAbstractContainer;
 import com.oracle.truffle.r.runtime.env.REnvironment;
 
-@RBuiltin(name = "names", kind = PRIMITIVE, parameterNames = {"x"})
+@RBuiltin(name = "names", kind = PRIMITIVE, parameterNames = {"x"}, dispatch = INTERNAL_GENERIC)
 public abstract class Names extends RBuiltinNode {
 
     private final ConditionProfile hasNames = ConditionProfile.createBinaryProfile();