Type narrowing breaks on equivalence to false.

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?

Type Checking

### Expected Behaviour

When `x` is a boolean, `if x == false then` should identify `x` as `false` in its true block, and `true` in its false block.

### Actual Behaviour

In the true block, `x` is identified as `true`, and in the false block, `x` is identified as `boolean`.

### Reproduction steps

1. Paste this code into the editor
```lua
local x ---@type boolean

if x == false then
local y = x
-- y is type `true`, should be type `false`
else
local y = x
-- y is type 'boolean', should be type 'true'
end
```
2. Hover over `y` to inspect its type.

### Additional Notes

This doesn't just happen with boolean types. It can happen to any type that can be `false`, such as `integer|false|nil`.

### Log File

_No response_

Reproduce the issue in the Visual Studio Code extension using the Lua snippet and hover over y in both branches. Trace the type-checking behavior for x == false, then verify that the true branch resolves to false and the false branch to true, including unions such as integer|false|nil.

Written by the indexing model from the issue text.