Can a type `T` be boxed in any case where `isbitstype(T)` gives `true`?

:jl_type_to_llvm can be used for checking whether a type is boxed or not, but if I have checked a type to be isbitstype, is there any need to check whether it is boxed using jl_type_to_llvm?

For example, is there a counter-example that can trigger the following assertion?

x = typeof(v)
if isbitstype(x)
     is_boxed = Ref{Bool}(false)
     @ccall jl_type_to_llvm(x::Any, is_boxed::Ptr{Bool})::Ptr{Cvoid}
     @assert !is_boxed[]
end