improve effects of factorial

[aviatesk]

So that it can be concrete-evaluated.

[Seelengrab]

Suggested change

	for T = Base.uniontypes(Union{Base.Checked.SignedInt,Base.Checked.UnsignedInt})
	@testset let T = T
	@test factorial(T(7)) == 5040
	@test Core.Compiler.is_foldable(Base.infer_effects(factorial, (T,)))
	end
	end
	types = Base.uniontypes(Union{Base.Checked.SignedInt,Base.Checked.UnsignedInt})
	@testset for T = types
	@test factorial(T(7)) == 5040
	@test Core.Compiler.is_foldable(Base.infer_effects(factorial, (T,)))
	end

[aviatesk]

I'd prefer the contextual testset.

[Seelengrab]

The @testset for will also show the iterated object as context on a failure, but aggregated and not as individual testsets:

julia> using Test

julia> types = Base.uniontypes(Union{Base.Checked.SignedInt,Base.Checked.UnsignedInt});

julia> @testset begin
       @testset for T = types
           @test factorial(T(7)) == 5040
           @test Core.Compiler.is_foldable(Base.infer_effects(factorial, (T,)))
       end
       end

[...]
Test Summary: | Pass  Fail  Total  Time
test set      |   10    10     20  0.4s
  T = Int128  |    1     1      2  0.0s
  T = Int16   |    1     1      2  0.0s
  T = Int32   |    1     1      2  0.0s
  T = Int64   |    1     1      2  0.0s
  T = Int8    |    1     1      2  0.0s
  T = UInt128 |    1     1      2  0.0s
  T = UInt16  |    1     1      2  0.0s
  T = UInt32  |    1     1      2  0.0s
  T = UInt64  |    1     1      2  0.0s
  T = UInt8   |    1     1      2  0.0s
ERROR: Some tests did not pass: 10 passed, 10 failed, 0 errored, 0 broken.

(run on a ~month old master, hence the failures)