[ruby/prism] Remove need for Natalie patches

https://github.com/ruby/prism/commit/7fc7e13476

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/prism/polyfill/string.rb b/lib/prism/polyfill/string.rb
index 582266d956..3fa9b5a0c5 100644
--- a/lib/prism/polyfill/string.rb
+++ b/lib/prism/polyfill/string.rb
@@ -1,7 +1,9 @@
 # frozen_string_literal: true
 
-# Polyfill for String#unpack1 with the offset parameter.
-if String.instance_method(:unpack1).parameters.none? { |_, name| name == :offset }
+# Polyfill for String#unpack1 with the offset parameter. Not all Ruby engines
+# have Method#parameters implemented, so we check the arity instead if
+# necessary.
+if (unpack1 = String.instance_method(:unpack1)).respond_to?(:parameters) ? unpack1.parameters.none? { |_, name| name == :offset } : (unpack1.arity == 1)
   String.prepend(
     Module.new {
       def unpack1(format, offset: 0) # :nodoc: