Solver fails in case of narrowing known type against truthy values

[OverHash]

Using the new type solver fails on degenerate cases when type checking

For example, in Roblox, the following code causes a type error:

--!strict

local function foo(player: Player)
    if player and player.Character and player.Character:FindFirstChild("Humanoid") then
        local humanoid = player.Character:FindFirstChildWhichIsA("Humanoid")
        assert(humanoid, `Failed to find {player.Character:GetFullName()}.Humanoid`)

        if player.Character:HasTag("someTag") then
            player.Character:FindFirstChild("RagdollConstraints"):Destroy()
        end
    end
end

Hovering over player inside the innermost if statement indicates the type is inferred as

refine<never, {
    Character: *blocked-5951724*
}>
Cannot call a value of type 'blocked-5951699'

[OverHash]

Hope the title is somewhat reasonable to describe the case, feel free to update.