Move RefactoringHelper to pooled obj. disposer.

src/Features/Core/Portable/CodeRefactorings/AbstractRefactoringHelpersService.cs

@@ -40,9 +40,8 @@ internal abstract class AbstractRefactoringHelpersService<TExpressionSyntax, TAr
                 return ImmutableArray<TSyntaxNode>.Empty;
             }
 
-            var relevantNodesBuilder = ArrayBuilder<TSyntaxNode>.GetInstance();
-            try
-            {
+            using var relevantNodesBuilderDisposer = ArrayBuilder<TSyntaxNode>.GetInstance(out var relevantNodesBuilder);
+
             // Every time a Node is considered an extractNodes method is called to add all nodes around the original one
             // that should also be considered.
             //
@@ -115,11 +114,6 @@ internal abstract class AbstractRefactoringHelpersService<TExpressionSyntax, TAr
 
             return relevantNodesBuilder.ToImmutable();
         }
-            finally
-            {
-                relevantNodesBuilder.Free();
-            }
-        }
 
         private static bool IsWantedTypeExpressionLike<TSyntaxNode>() where TSyntaxNode : SyntaxNode
         {