Generalize exception type

In preparation for JuliaLang/julia#41885

Author: timholy

test/util/iterator.jl

@@ -19,15 +19,15 @@ end
     @test sortstablemax([1, 4, 2, 7, 5]) == 7
     @test sortstablemax([8:10, 1:3, [], 4:23, 1:9], by=length) == 4:23
     @test sortstablemax([8:10, 1:3, 3:22, 4:23, 1:9], by=length) == 3:22
-    @test_throws ArgumentError sortstablemax([])
+    @test_throws Union{ArgumentError,MethodError} sortstablemax([])
     @test sortstablemax([], init=0) == 0
 end
 
 @testset "sortstablemin" begin
     @test sortstablemin([1, 4, 2, 7, 5]) == 1
     @test sortstablemin([8:10, 1:3, [], 4:23, 1:9], by=length) == []
     @test sortstablemin([8:10, 1:3, 3:22, 4:23, 1:9], by=length) == 8:10
-    @test_throws ArgumentError sortstablemin([])
+    @test_throws Union{ArgumentError,MethodError} sortstablemin([])
     @test sortstablemin([], init=0) == 0
 end
 end # util.iterator