invalid "Impossible `if` statement: this condition is always falsy [unnecessary-if]"

[MagicDuck]

Hello! 👋
Thank you for your hard work on this amazing language server!

I have run into a pattern where unnecessary-if / unused rules do not seem to function correctly. Observe below (this is a simplified example, but the pattern occurs in more complex code):

The if-statement should not be "impossible" and bar should not be "unused".

This is the code to easily reproduce:

local mytable = {}
local bar = nil
function foo()
  if bar then
    table.insert(mytable, 'hello')
  end
end

bar = true
foo()

[CppCXY]

I think disabling this diagnostic is the quickest solution for now.