Find where second-order is failing and create further issues to fix

Summary:

@syclik claims that if we try to build all the models in stan-dev/stan/test-models/good for fvar<var> that they will break because second-order autodiff isn't complete.

Description:

These are the functions that we can't compile using stan::math::fvar<double> and/or stan::math::fvar<stan::math::var>:

• stan/math/prim/scal/fun/inc_beta.hpp
• stan/math/prim/mat/fun/quad_form.hpp
• prim/mat/fun/trace_gen_quad_form.hpp

And all the ODE functionality:

• stan/math/rev/mat/functor/cvodes_ode_data.hpp
• stan/math/rev/arr/fun/decouple_ode_states.hpp
• stan/math/rev/mat/functor/integrate_ode_bdf.hpp
• stan/math/rev/mat/functor/cvodes_ode_data.hpp
• stan/math/rev/arr/fun/decouple_ode_states.hpp
• stan/math/prim/arr/functor/integrate_ode_rk45.hpp

Reproducible Steps:

Need to hack the test in stan-dev/stan to compile for second-order or do something else similar like create a new make target.

Current Output:

Failing?

Expected Output:

Everything buildable.

Current Version:

v2.12.0