RArguments.setArgument is no longer required

com.oracle.truffle.r.nodes/src/com/oracle/truffle/r/nodes/access/AccessArgumentNode.java

@@ -40,7 +40,6 @@ import com.oracle.truffle.r.nodes.function.PromiseHelperNode;
 import com.oracle.truffle.r.nodes.function.opt.EagerEvalHelper;
 import com.oracle.truffle.r.nodes.function.opt.OptConstantPromiseNode;
 import com.oracle.truffle.r.nodes.function.opt.OptVariablePromiseBaseNode;
-import com.oracle.truffle.r.runtime.RArguments;
 import com.oracle.truffle.r.runtime.RInternalError;
 import com.oracle.truffle.r.runtime.data.REmpty;
 import com.oracle.truffle.r.runtime.data.RMissing;
@@ -113,13 +112,9 @@ public final class AccessArgumentNode extends RNode {
         assert !(getRootNode() instanceof RBuiltinRootNode) : getRootNode();
         // Insert default value
         checkPromiseFactory();
-        Object result;
         if (canBeOptimized()) {
             if (checkInsertOptDefaultArg()) {
-                result = optDefaultArgNode.execute(frame);
-                // Update RArguments for S3 dispatch to work
-                RArguments.setArgument(frame, index, result);
-                return result;
+                return optDefaultArgNode.execute(frame);
             } else {
                 /*
                  * Default arg cannot be optimized: Rewrite to default and assure that we don't take
@@ -130,10 +125,7 @@ public final class AccessArgumentNode extends RNode {
             }
         }
         // Insert default value
-        result = factory.createPromise(frame.materialize());
-        // Update RArguments for S3 dispatch to work
-        RArguments.setArgument(frame, index, result);
-        return result;
+        return factory.createPromise(frame.materialize());
     }
 
     private Object doArgument(VirtualFrame frame, Object arg) {

com.oracle.truffle.r.runtime/src/com/oracle/truffle/r/runtime/RArguments.java

@@ -264,18 +264,6 @@ public final class RArguments {
         return Arrays.copyOfRange(args, INDEX_ARGUMENTS, INDEX_ARGUMENTS + getArgumentsLength(frame));
     }
 
-    /**
-     * <b>Only to be called from AccessArgumentNode!</b>
-     *
-     * @param frame
-     * @param argIndex
-     * @param newValue
-     */
-    public static void setArgument(Frame frame, int argIndex, Object newValue) {
-        assert (argIndex >= 0 && argIndex < getNArgs(frame));
-        frame.getArguments()[INDEX_ARGUMENTS + argIndex] = newValue;
-    }
-
     public static int getArgumentsLength(Frame frame) {
         return getNArgs(frame);
     }