Update ripper_supported? for truffleruby and ripper specs to only run…

… when supported

lib/rspec/support/ruby_features.rb

@@ -47,6 +47,10 @@ def non_mri?
       def mri?
         !defined?(RUBY_ENGINE) || RUBY_ENGINE == 'ruby'
       end
+
+      def truffleruby?
+        defined?(RUBY_ENGINE) && RUBY_ENGINE == 'truffleruby'
+      end
     end
 
     # @api private
@@ -101,7 +105,7 @@ def supports_taint?
       end
       ripper_requirements = [ComparableVersion.new(RUBY_VERSION) >= '1.9.2']
 
-      ripper_requirements.push(false) if Ruby.rbx?
+      ripper_requirements.push(false) if Ruby.rbx? || Ruby.truffleruby?
 
       if Ruby.jruby?
         ripper_requirements.push(Ruby.jruby_version >= '1.7.5')

spec/rspec/support/ruby_features_spec.rb

@@ -123,6 +123,10 @@ def ripper_works_correctly?
             ripper_can_parse_source_including_keywordish_symbol?
         end
 
+        def self.ripper_supported?
+          RubyFeatures.ripper_supported?
+        end
+
         # https://github.com/jruby/jruby/issues/3386
         def ripper_reports_correct_line_number?
           in_sub_process_if_possible do
@@ -144,7 +148,7 @@ def ripper_can_parse_source_including_keywordish_symbol?
           end
         end
 
-        it 'returns whether Ripper is correctly implemented in the current environment' do
+        it 'returns whether Ripper is correctly implemented in the current environment', :if => ripper_supported? do
           expect(RubyFeatures.ripper_supported?).to eq(ripper_is_implemented? && ripper_works_correctly?)
         end