Unable to define anonymous object with "class" property

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Describe the bug

I am migrating code from MVC5 which uses anonymous objects to define the attribute:

```
@{
var htmlAttributesObject = ViewData["htmlAttributes"];
var defaultHtmlAttributesObject = new { @class = "form-control", ... };
var htmlAttributes = Html.MergeHtmlAttributes(htmlAttributesObject, defaultHtmlAttributesObject);
}
```

When I attempt to build, I get an error:

> Error RZ1007: "class" is a reserved word and cannot be used in implicit expressions. An explicit expression ("@()") must be used.

According to #15004 from 2019, the "solution" is to use a double "@" - ie:

```
var defaultHtmlAttributesObject = new { @@class = "form-control", ... };
```

But if I do that, I get:

> Error CS0746: Invalid anonymous type member declarator. Anonymous type members must be declared with a member assignment, simple name or member access.

### Expected Behavior

It should be possible to migrate this code to .NET without errors, either using the original syntax, or the revised syntax from #15004.

### Steps To Reproduce

* Create a new ASP.NET Core MVC project.
* Open `Views/Home/Index.cshtml`.
* Within the code block, attempt to define an anonymous object with a `class` property:

```
@{
ViewData["Title"] = "Home Page";

var htmlAttributes1 = new { @class = "form-control" };
var htmlAttributes2 = new { @@class = "form-control" };
}
```

* Attempt to build the project.

[RichardD2/AspNetCoreClassAttribute](https://github.com/RichardD2/AspNetCoreClassAttribute)

### Exceptions (if any)

The double-@ prefix shows as an error in the editor; the original version does not.

Both versions generate errors on build:

> Error RZ1007: "class" is a reserved word and cannot be used in implicit expressions. An explicit expression ("@()") must be used.
> Error CS1525: Invalid expression term '='
> Error CS0746: Invalid anonymous type member declarator. Anonymous type members must be declared with a member assignment, simple name or member access.

### .NET Version

8.0.303

### Anything else?

ASP.NET Core 8.0.7
VS2022 v17.10.5
Windows 11 23H2

`dotnet --info` output:

> .NET SDK:
> Version: 8.0.303
> Commit: 29ab8e3268
> Workload version: 8.0.300-manifests.34944930
> MSBuild version: 17.10.4+10fbfbf2e
>
> Runtime Environment:
> OS Name: Windows
> OS Version: 10.0.22631
> OS Platform: Windows
> RID: win-x64
> Base Path: C:\Program Files\dotnet\sdk\8.0.303\
>
> .NET workloads installed:
> [wasm-tools]
> Installation Source: VS 17.10.35122.118
> Manifest Version: 8.0.7/8.0.100
> Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.workload.mono.toolchain.current\8.0.7\WorkloadManifest.json
> Install Type: FileBased
>
> [maui-windows]
> Installation Source: VS 17.10.35122.118
> Manifest Version: 8.0.61/8.0.100
> Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.maui\8.0.61\WorkloadManifest.json
> Install Type: FileBased
>
> [maccatalyst]
> Installation Source: VS 17.10.35122.118
> Manifest Version: 17.2.8053/8.0.100
> Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.maccatalyst\17.2.8053\WorkloadManifest.json
> Install Type: FileBased
>
> [ios]
> Installation Source: VS 17.10.35122.118
> Manifest Version: 17.2.8053/8.0.100
> Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.ios\17.2.8053\WorkloadManifest.json
> Install Type: FileBased
>
> [aspire]
> Installation Source: VS 17.10.35122.118
> Manifest Version: 8.0.0/8.0.100
> Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.aspire\8.0.0\WorkloadManifest.json
> Install Type: FileBased
>
> [android]
> Installation Source: VS 17.10.35122.118
> Manifest Version: 34.0.95/8.0.100
> Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.android\34.0.95\WorkloadManifest.json
> Install Type: FileBased
>
>
> Host:
> Version: 8.0.7
> Architecture: x64
> Commit: 2aade6beb0
>
> .NET SDKs installed:
> 5.0.101 [C:\Program Files\dotnet\sdk]
> 5.0.103 [C:\Program Files\dotnet\sdk]
> 5.0.403 [C:\Program Files\dotnet\sdk]
> 5.0.408 [C:\Program Files\dotnet\sdk]
> 5.0.416 [C:\Program Files\dotnet\sdk]
> 6.0.202 [C:\Program Files\dotnet\sdk]
> 6.0.424 [C:\Program Files\dotnet\sdk]
> 7.0.410 [C:\Program Files\dotnet\sdk]
> 8.0.303 [C:\Program Files\dotnet\sdk]
>
> .NET runtimes installed:
> Microsoft.AspNetCore.All 2.1.25 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
> Microsoft.AspNetCore.All 2.1.27 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
> Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
> Microsoft.AspNetCore.App 2.1.25 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 2.1.27 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 3.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 3.1.14 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 3.1.25 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 3.1.26 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 5.0.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 5.0.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 5.0.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 6.0.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 6.0.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.AspNetCore.App 8.0.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
> Microsoft.NETCore.App 2.1.25 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 2.1.26 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 2.1.27 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 3.1.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 3.1.14 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 3.1.25 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 3.1.26 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 5.0.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 5.0.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 5.0.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 6.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 6.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 6.0.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 6.0.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.NETCore.App 8.0.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
> Microsoft.WindowsDesktop.App 3.1.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 3.1.13 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 3.1.14 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 3.1.25 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 3.1.26 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 5.0.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 5.0.3 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 5.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 5.0.10 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 5.0.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 6.0.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 6.0.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 6.0.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 7.0.20 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
> Microsoft.WindowsDesktop.App 8.0.7 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
>
> Other architectures found:
> arm64 [C:\Program Files\dotnet]
> registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\arm64\InstallLocation]
> x86 [C:\Program Files (x86)\dotnet]
> registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]
>
> Environment variables:
> Not set
>
> global.json file:
> Not found