isnan check on NamedTuples with nested vectors fails

[penelopeysm]

Following from #888, this code errors (reported by Christopher Fisher on Slack):

using SequentialSamplingModels
using Turing

@model function model(data; min_rt = minimum(data[2]))
    ν ~ MvNormal(zeros(2), I * 2)
    A ~ truncated(Normal(0.8, 0.4), 0.0, Inf)
    k ~ truncated(Normal(0.2, 0.2), 0.0, Inf)
    τ ~ Uniform(0.0, min_rt)
    data ~ LBA(; ν, A, k, τ)
end

# generate some data
dist = LBA(ν = [3.0, 2.0], A = 0.8, k = 0.2, τ = 0.3)
data = rand(dist, 100)

# estimate parameters
chain = sample(model(data), NUTS(200, 0.65), 100)

errors because sampling from LBA returns a NamedTuple which contains a vector of parameters, and any(isnan, τ) doesn't know how to recurse.

ERROR: MethodError: no method matching isnan(::Vector{Int64})
The function `isnan` exists, but no method is defined for this combination of argument types.

Closest candidates are:
  isnan(::Missing)
   @ Base missing.jl:101
  isnan(::BigFloat)
   @ Base mpfr.jl:1044
  isnan(::ForwardDiff.Dual)
   @ ForwardDiff ~/.julia/packages/ForwardDiff/UBbGT/src/dual.jl:389
  ...

Stacktrace:
  [1] _any(f::typeof(isnan), itr::@NamedTuple{choice::Vector{Int64}, rt::Vector{Float64}}, ::Colon)
    @ Base ./reduce.jl:1237
  [2] any(f::Function, itr::@NamedTuple{choice::Vector{Int64}, rt::Vector{Float64}})
    @ Base ./reduce.jl:1228
  [3] record_pre_tilde_observe!(context::DynamicPPL.DebugUtils.DebugContext{…}, left::@NamedTuple{…}, dist::LNR{…}, varinfo::DynamicPPL.UntypedVarInfo{…})
    @ DynamicPPL.DebugUtils ~/.julia/packages/DynamicPPL/Ka4RU/src/debug_utils.jl:294
  [4] tilde_observe(context::DynamicPPL.DebugUtils.DebugContext{…}, right::LNR{…}, left::@NamedTuple{…}, vi::DynamicPPL.UntypedVarInfo{…})
    @ DynamicPPL.DebugUtils ~/.julia/packages/DynamicPPL/Ka4RU/src/debug_utils.jl:317
  [5] tilde_observe!!(context::DynamicPPL.DebugUtils.DebugContext{…}, right::LNR{…}, left::@NamedTuple{…}, vi::DynamicPPL.UntypedVarInfo{…})
    @ DynamicPPL ~/.julia/packages/DynamicPPL/Ka4RU/src/context_implementations.jl:194
  [6] tilde_observe!!(context::DynamicPPL.DebugUtils.DebugContext{…}, right::LNR{…}, left::@NamedTuple{…}, vname::AbstractPPL.VarName{…}, vi::DynamicPPL.UntypedVarInfo{…})
    @ DynamicPPL ~/.julia/packages/DynamicPPL/Ka4RU/src/context_implementations.jl:176
  [7] macro expansion
    @ ~/.julia/packages/DynamicPPL/Ka4RU/src/compiler.jl:574 [inlined]
  [8] model(__model__::DynamicPPL.Model{…}, __varinfo__::DynamicPPL.UntypedVarInfo{…}, __context__::DynamicPPL.DebugUtils.DebugContext{…}, data::@NamedTuple{…}; min_rt::Float64)
    @ Main ~/.julia/dev/sandbox/turing/run_turing.jl:17
  [9] _evaluate!!(model::DynamicPPL.Model{…}, varinfo::DynamicPPL.UntypedVarInfo{…}, context::DynamicPPL.DebugUtils.DebugContext{…})
    @ DynamicPPL ~/.julia/packages/DynamicPPL/Ka4RU/src/model.jl:936
 [10] evaluate_threadunsafe!!(model::DynamicPPL.Model{…}, varinfo::DynamicPPL.UntypedVarInfo{…}, context::DynamicPPL.DebugUtils.DebugContext{…})
    @ DynamicPPL ~/.julia/packages/DynamicPPL/Ka4RU/src/model.jl:909
 [11] check_model_and_trace(rng::TaskLocalRNG, model::DynamicPPL.Model{…}; varinfo::DynamicPPL.UntypedVarInfo{…}, context::DynamicPPL.SamplingContext{…}, error_on_failure::Bool, kwargs::@Kwargs{})
    @ DynamicPPL.DebugUtils ~/.julia/packages/DynamicPPL/Ka4RU/src/debug_utils.jl:457
 [12] check_model_and_trace(model::DynamicPPL.Model{…}; kwargs::@Kwargs{…})
    @ DynamicPPL.DebugUtils ~/.julia/packages/DynamicPPL/Ka4RU/src/debug_utils.jl:438
 [13] check_model(model::DynamicPPL.Model{…}; kwargs::@Kwargs{…})
    @ DynamicPPL.DebugUtils ~/.julia/packages/DynamicPPL/Ka4RU/src/debug_utils.jl:483
 [14] _check_model(model::DynamicPPL.Model{…})
    @ Turing.Inference ~/.julia/packages/Turing/IXycm/src/mcmc/Inference.jl:253
 [15] _check_model(model::DynamicPPL.Model{…}, alg::NUTS{…})
    @ Turing.Inference ~/.julia/packages/Turing/IXycm/src/mcmc/Inference.jl:256
 [16] sample(rng::TaskLocalRNG, model::DynamicPPL.Model{…}, alg::NUTS{…}, N::Int64; check_model::Bool, kwargs::@Kwargs{})
    @ Turing.Inference ~/.julia/packages/Turing/IXycm/src/mcmc/Inference.jl:277
 [17] sample(rng::TaskLocalRNG, model::DynamicPPL.Model{…}, alg::NUTS{…}, N::Int64)
    @ Turing.Inference ~/.julia/packages/Turing/IXycm/src/mcmc/Inference.jl:269
 [18] sample(model::DynamicPPL.Model{…}, alg::NUTS{…}, N::Int64; kwargs::@Kwargs{})
    @ Turing.Inference ~/.julia/packages/Turing/IXycm/src/mcmc/Inference.jl:266
 [19] sample(model::DynamicPPL.Model{…}, alg::NUTS{…}, N::Int64)
    @ Turing.Inference ~/.julia/packages/Turing/IXycm/src/mcmc/Inference.jl:263
 [20] top-level scope
    @ ~/.julia/dev/sandbox/turing/run_turing.jl:25
Some type information was truncated. Use `show(err)` to see complete types.