missing-fields ignores fields set post-assignment

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

Assigning a table to a variable with @type annotation and filling out the class's fields and functions afterwards should not trigger missing-fields.

Actual Behaviour

A missing-fields diagnostic is triggered despite fields being set after the initial assignment of the variable yet before the variable is used for anything.

Reproduction steps

Small script that replicates the issue:

---@class MyInterface
---@field DoAction fun()

---@type MyInterface
local inst = {}

-- Does not remove `missing-fields` diagnostic
inst.DoAction = function() end

missing-fields will trigger on inst.

Additional Notes

No response

Log File

No response

Start with the Lua reproduction in the issue and trace the missing-fields diagnostic for a typed table whose field is assigned after initialization. Confirm the behavior in the Visual Studio Code extension on Windows; done means the post-assignment field no longer produces a missing-fields diagnostic before the variable is used.