Only run Test.jl precompilation workload when outputting (JuliaLang#5…

…4045)

These types of workloads are usually only run when generating output.

stdlib/Test/src/precompile.jl

@@ -1,9 +1,11 @@
-redirect_stdout(devnull) do
- @testset "example" begin
- @test 1 == 1
- @test_throws ErrorException error()
- @test_logs (:info, "Doing foo with n=2") @info "Doing foo with n=2"
- @test_broken 1 == 2
- @test 1 ≈ 1.0000000000000001
+if Base.generating_output()
+ redirect_stdout(devnull) do
+ @testset "example" begin
+ @test 1 == 1
+ @test_throws ErrorException error()
+ @test_logs (:info, "Doing foo with n=2") @info "Doing foo with n=2"
+ @test_broken 1 == 2
+ @test 1 ≈ 1.0000000000000001
+ end
  end
 end