fails:Regexp#eql? is true if self and other have the same pattern
fails:Regexp#eql? is true if self and other have the same character set code
fails:Regexp#eql? is true if other has the same #casefold? values
fails:Regexp#eql? is true if self does not specify /n option and other does
fails:Regexp#eql? is true if self specifies /n option and other does not
