Add iterate for Reverse{<:NamedTuple} (#43038)

Fixes the problem mentioned in #42991 (comment)

base/iterators.jl

@@ -118,7 +118,7 @@ reverse(r::Reverse) = r.itr
 reverse(x::Union{Number,AbstractChar}) = x
 reverse(p::Pair) = Base.reverse(p) # copying pairs is cheap
 
-iterate(r::Reverse{<:Tuple}, i::Int = length(r.itr)) = i < 1 ? nothing : (r.itr[i], i-1)
+iterate(r::Reverse{<:Union{Tuple, NamedTuple}}, i::Int = length(r.itr)) = i < 1 ? nothing : (r.itr[i], i-1)
 
 # enumerate
 

test/iterators.jl

@@ -687,17 +687,19 @@ end
     for itr in (2:10, "∀ϵ>0", 1:0, "", (2,3,5,7,11), [2,3,5,7,11], rand(5,6), Z, 3, true, 'x', 4=>5,
                 eachindex("∀ϵ>0"), view(Z), view(rand(5,6),2:4,2:6), (x^2 for x in 1:10),
                 Iterators.Filter(isodd, 1:10), flatten((1:10, 50:60)), enumerate("foo"),
-                pairs(50:60), zip(1:10,21:30,51:60), product(1:3, 10:12), repeated(3.14159, 5))
+                pairs(50:60), zip(1:10,21:30,51:60), product(1:3, 10:12), repeated(3.14159, 5),
+                (a=2, b=3, c=5, d=7, e=11))
         @test squash(collect(Iterators.reverse(itr))) == reverse(squash(collect(itr)))
     end
     @test collect(take(Iterators.reverse(cycle(1:3)), 7)) == collect(take(cycle(3:-1:1), 7))
     let r = repeated(3.14159)
         @test Iterators.reverse(r) === r
     end
-    let t = (2,3,5,7,11)
+    for t in [(1,), (2, 3, 5, 7, 11), (a=1,), (a=2, b=3, c=5, d=7, e=11)]
         @test Iterators.reverse(Iterators.reverse(t)) === t
         @test first(Iterators.reverse(t)) === last(t)
         @test last(Iterators.reverse(t)) === first(t)
+        @test collect(Iterators.reverse(t)) == reverse(collect(t))
     end
 end