In test/ruby/enc/test_case_mapping.rb, add a test to make sure the
unassigned codepoints in the Georgian MTAVRULI range (U+1CBB, U+1CBC)
do not get converted to unrelated codepoints by String#capitalize.
(It turns out that this test was not strictly necessary, because
unassigned codepoints are already excluded by the fact that they are
not found in the onigenc_unicode_fold_lookup table. So this test only
serves to check against future regressions.)

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66314 b2dd03c8-39d4-4d8f-98ff-823fe69b080e