Avoid infinite type recursion in type inference

[yuyichao]

See point 2 in JuliaLang/LinearAlgebra.jl#283

A minimum repro is,

type A{T}
end

A{T}(a::T) = A{T}()

function f(a)
    if rand() > 100
        return f(A(a))
    end
end

@code_warntype f(1)

Even though the recursion path will never be executed, type inference will still try to infer the type of the recursion call with a infinitely deep type and even if there's a genuine infinite recursion, it's better to do that at runtime and not in type inference.....

We already have a bunch of limit on type length so I think we should probably also have some limit here.

@carnaval Does green-fairy provide any general solution to these problems?