* compar.c (cmp_equal): warn for this release and still rescue
  standard exceptions for a nicer transition. See #7688.
  Partly reverts r44502.
* test/ruby/test_comparable.rb: adapt assertion to match new behavior.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44646 b2dd03c8-39d4-4d8f-98ff-823fe69b080e