Multiline definitions bug in @meta files

Nobody has claimed this yet.

### 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?

Diagnostics/Syntax Checking

### Expected Behaviour

Not throwing a warning

### Actual Behaviour

Throws a warning for this piece of code: for missing return
```lua
---@meta

-- bunch of other definitions

---Create a new RotMatrix.
---Available in worker threads.
---@param x1 number
---@param y1 number
---@param z1 number
---@param x2 number
---@param y2 number
---@param z2 number
---@param x3 number
---@param y3 number
---@param z3 number
---@return RotMatrix rotMatrix The created rotation matrix.
function RotMatrix(
x1, y1, z1,
x2, y2, z2,
x3, y3, z3
) end
```

But not for the same code, with the RotMatrix shortened to 1 line;
```
function RotMatrix(x1, y1, z1, x2, y2, z2, x3, y3, z3) end
```

### Reproduction steps

1. Check code sample in editor

### Additional Notes

_No response_

### Log File

_No response_

Start by reproducing the Lua sample in the Visual Studio Code extension and tracing the diagnostics/syntax-checking report for the multiline RotMatrix definition. Compare it with the one-line definition; done when the multiline @meta definition no longer reports a missing-return warning while the reported behavior remains correct.

Written by the indexing model from the issue text.