* test/-ext-/num2int/test_num2int.rb: extract
  assert_num2i_success_internal and assert_num2i_error_internal and
  provide assertion messages as "NUM2XXX(NNN)".


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39981 b2dd03c8-39d4-4d8f-98ff-823fe69b080e