* test/ruby/test_dir.rb, test/ruby/test_fnmatch.rb: add some tests
  (for coverage of dir.c).

* test/ruby/test_enum.rb: add a test for Enumerable#minmax.

* test/ruby/test_enumerator.rb: add some tests for Enumerator#inspect,
  Enumerator::Generator and Yielder.

* test/ruby/test_env.rb: add a test for ENV#index.

* test/ruby/test_exception.rb: add some tests (for coverage of
  error.c).

* test/ruby/test_hash.rb: add a test for recursive check.

* test/ruby/test_integer.rb: add a test for number of argument of
  Integer.

* test/ruby/test_method.rb: add a test for define_method.

* test/ruby/test_module.rb: add a test for constant of included
  module.

* test/ruby/test_proc.rb: add a test for parameters with cfunc.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@26379 b2dd03c8-39d4-4d8f-98ff-823fe69b080e