Set parameter name token as relevant node for parameter declaration

actions.

ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/CheckIfParameterIsNullAction.cs

@@ -55,7 +55,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 					TrueStatement = new ThrowStatement (new ObjectCreateExpression (context.CreateShortType("System", "ArgumentNullException"), new PrimitiveExpression (parameter.Name)))
 				};
 				script.AddTo(bodyStatement, statement);
-			}, parameter);
+			}, parameter.NameToken);
 		}
 
 		static bool HasNullCheck (ParameterDeclaration parameter)

ICSharpCode.NRefactory.CSharp/Refactoring/CodeActions/CreateOverloadWithoutParameterAction.cs

@@ -84,7 +84,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 
 					//if (node.ParameterModifier != ParameterModifier.Out)
 					//    script.Link (defaultExpr);
-				}, node); 
+				}, node.NameToken); 
 		}
 
 		static Expression GetArgumentExpression(ParameterDeclaration parameter)