t push origin mt/:Merge branch 'mt/fixes_threaded' of https://github.com/TuringLang/DynamicPPL.jl into mt/fixes_threaded

Author: mohamed82008

src/compat/ad.jl

@@ -7,12 +7,12 @@ ZygoteRules.@adjoint function push!(
     dist::Distribution,
     gidset::Set{Selector}
 )
-    return push!(vi, vn, r, dist, gidset), _ -> ntuple(_ -> nothing, 5)
+    return push!(vi, vn, r, dist, gidset), _ -> nothing
 end
 
 ZygoteRules.@adjoint function Threads.nthreads()
-    Threads.nthreads(), _ -> (nothing,)
+    return Threads.nthreads(), _ -> nothing
 end
 ZygoteRules.@adjoint function Threads.threadid()
-    Threads.threadid(), _ -> (nothing,)
+    return Threads.threadid(), _ -> nothing
 end