increase timeout for ARMv7

	http://rubyci.s3.amazonaws.com/scw-9d6766/ruby-trunk/log/20160113T091704Z.diff.html.gz
	* test/ruby/test_array.rb: split out the test for no stack error
	  on large input for test_permutation, test_repeated_permutation,
	  and test_repeated_combination, and make them all timeout:30.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@56002 b2dd03c8-39d4-4d8f-98ff-823fe69b080e