Follow up JuliaLang#45236, make length(::StepRange{Int8,Int128}) stable

Author: N5N3

base/range.jl

@@ -799,7 +799,7 @@ let smallints = (Int === Int64 ?
     function length(r::OrdinalRange{<:smallints})
         s = step(r)
         isempty(r) && return 0
-        return div(Int(last(r)) - Int(first(r)), s) + 1
+        return Int(div(Int(last(r)) - Int(first(r)), s)) + 1
     end
     length(r::AbstractUnitRange{<:smallints}) = Int(last(r)) - Int(first(r)) + 1
     length(r::OneTo{<:smallints}) = Int(r.stop)

test/ranges.jl

@@ -2032,7 +2032,8 @@ end
 end
 
 @testset "length(StepRange()) type stability" begin
-    typeof(length(StepRange(1,Int128(1),1))) == typeof(length(StepRange(1,Int128(1),0)))
+    typeof(length(StepRange(1,Int128(1),1))) == typeof(length(StepRange(1,Int128(1),0))) #bigints
+    typeof(length(StepRange(Int8(1),Int128(1),Int8(1)))) == typeof(length(StepRange(Int8(1),Int128(1),Int8(0)))) #smallints
     typeof(checked_length(StepRange(1,Int128(1),1))) == typeof(checked_length(StepRange(1,Int128(1),0)))
 end