Update ripper_supported? for truffleruby and specs ripper_is_implemented?

Author: bjfish

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

@@ -111,7 +111,7 @@ def ripper_is_implemented?
           in_sub_process_if_possible do
             begin
               require 'ripper'
-              !!defined?(::Ripper)
+              !!defined?(::Ripper) && Ripper.respond_to?(:lex)
             rescue LoadError
               false
             end