Ruby

re.c: fix wchar match at EOS

• re.c (rb_memsearch_wchar, rb_memsearch_qchar): test matching
  till the end of string. [ruby-core:70592] [Bug #11488]
• test/ruby/test_m17n.rb (test_include?, tet_index): add tests by
  Tom Stuart.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51685 b2dd03c8-39d4-4d8f-98ff-823fe69b080e