VM.OnCompileFunctionParam does not work at all

Chưa có ai nhận issue này.

### How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

### Which OS are you using?

Windows

### What is the issue affecting?

Plugins

### Expected Behaviour

According to [https://luals.github.io/wiki/plugins/#vmoncompilefunctionparam](url), `VM.OnCompileFunctionParam()` is supposed to work.

### Actual Behaviour

It simply does not work, and throws this error instead:
```
2026-01-28 20:58:08.342 [info] C:\Path\plugin.lua:4: attempt to index a nil value (global 'VM')
stack traceback:
C:\Path\plugin.lua:4: in main chunk
[C]: in global 'xpcall'
script\plugin.lua:157: in function

2026-01-28 20:58:08.348 [info] [Error - 8:58:08 PM] An error occurred in the plugin, please report it to the plugin author.
Please check the details in the output or log.
Plugin path: C:\Path\plugin.lua
```

### Reproduction steps

1. Write `function VM.OnCompileFunctionParam(next, func, param) end` in plugin.lua
2. Add `"Lua.runtime.plugin": "C:/Path/plugin.lua"` to `.vscode/settings.json` or similar
3. The error happens

### Additional Notes

Please note that `OnSetText()` works as advertised, so the plugin system works; it is only this specific feature that does not seem to be working correctly.

For context, my library has JS-style event callbacks that work roughly like this:
```Lua
addHook("PlayerUpdate", function(player)
end)
```
As you probably guessed already, I was hoping to use `VM.OnCompileFunctionParam()` to make it detect the parameter's type without requiring explicitly annotations, since generics do not seem to support this pattern at the moment?
I could also use `OnSetText()` instead, but it sounds like a less reliable method as it depends on the formatting, and it would also cause a warning about duplicate annotations if the user typed the `---@param` explicitly.

### Log File

_No response_

Bắt đầu bằng việc tái hiện plugin trong plugin.lua và đường dẫn tải được tham chiếu bởi script\plugin.lua:157, sau đó so sánh điểm vào VM.OnCompileFunctionParam được ghi trong tài liệu với hook OnSetText đang hoạt động. Tái hiện lỗi VM nil bằng cấu hình .vscode/settings.json được hiển thị. Được xem là hoàn tất khi callback có thể được định nghĩa và gọi mà không có lỗi VM toàn cục.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.