Type inference ignores loops

[NyakoFox]

This works:

---@class MyClass

local thing = nil
if true then
    thing = {} --[[@as MyClass]]
end

-- thing is now MyClass?

This doesn't:

---@class MyClass

local thing = nil
for i = 1, 10 do
    thing = {} --[[@as MyClass]]
end

-- thing is nil

happens for while as well:

---@class MyClass

local thing = nil
while true do
    thing = {} --[[@as MyClass]]
    break
end

-- thing is nil

[xuhuanzy]

@lewis6991 Could you take a look?