add inference test

Author: N5N3

test/broadcast.jl

@@ -779,6 +779,9 @@ let
     bc = Broadcasted(+, (Broadcasted(*, (1, Broadcasted(/, (2.0, 2.5)))), Broadcasted(*, (Broadcasted(*, (3, 4)), 5))))
     @test @inferred(Broadcast.cat_nested(bc)) == (1,2.0,2.5,3,4,5)
     @test @inferred(Broadcast.materialize(Broadcast.flatten(bc))) == @inferred(Broadcast.materialize(bc)) == 60.8
+    # 1 .* 1 .- 1 .* 1 .^2 .+ 1 .* 1 .+ 1 .^ 3
+    bc = Base.Broadcast.Broadcasted(+, (Base.Broadcast.Broadcasted(+, (Base.Broadcast.Broadcasted(-, (Base.Broadcast.Broadcasted(*, (1, 1)), Base.Broadcast.Broadcasted(*, (1, Base.Broadcast.Broadcasted(Base.literal_pow, (Base.RefValue{typeof(^)}(^), 1, Base.RefValue{Val{2}}(Val{2}()))))))), Base.Broadcast.Broadcasted(*, (1, 1)))), Base.Broadcast.Broadcasted(Base.literal_pow, (Base.RefValue{typeof(^)}(^), 1, Base.RefValue{Val{3}}(Val{3}()))))) 
+    @test @inferred(Broadcast.materialize(Broadcast.flatten(bc))) == @inferred(Broadcast.materialize(bc)) == 2
 end
 
 let