simplify

src/Features/Core/Portable/AddImport/CodeActions/InstallPackageAndAddImportCodeAction.cs

@@ -51,10 +51,10 @@ protected override async Task<IEnumerable<CodeActionOperation>> ComputePreviewOp
                 var solutionChangeAction = new SolutionChangeAction(
                     "", c => GetUpdatedSolutionAsync(c));
 
-                var result = ArrayBuilder<CodeActionOperation>.GetInstance();
+                using var _ = ArrayBuilder<CodeActionOperation>.GetInstance(out var result);
                 result.AddRange(await solutionChangeAction.GetPreviewOperationsAsync(cancellationToken).ConfigureAwait(false));
                 result.Add(_installOperation);
-                return result.ToImmutableAndFree();
+                return result.ToImmutable();
             }
 
             private async Task<Solution> GetUpdatedSolutionAsync(CancellationToken cancellationToken)