Mark failing examples on JRuby 9000 as pending

[yujinakayama]

They have started failing after we made ripper_supported? return true on JRuby 9.1.9.0 or later in rspec/rspec-support#326. However it's actually caused by a bug in JRuby's backtrace, neither Ripper nor our multiline snippet extraction.

jruby/jruby#4737

Failures:

  1) RSpec::Core::Formatters::ExceptionPresenter#read_failed_lines when the failed expression spans multiple lines and the line count does not exceed RSpec.configuration.max_displayed_failure_line_count returns all the lines
     Failure/Error:
       expect(read_failed_lines).to eq([
         "            expect('RSpec').to be_a(String).",
         "                           and start_with('R').",
         "                           and end_with('z')"
       ])

       expected: ["            expect('RSpec').to be_a(String).", "                           and start_with('R').", "                           and end_with('z')"]
            got: ["                           and start_with('R').", "                           and end_with('z')"]

       (compared using ==)

[yujinakayama]

@rspec/rspec