Implement rb_error_frozen_object.

Author: nirvdrum

CHANGELOG.md

@@ -21,6 +21,7 @@ Compatibility:
 * Joni has been updated from 2.2.1 to 2.2.6 (@andrykonchin).
 * Fix numeric coercing when `#coerce` method is not public (#3848, @andrykonchin).
 * Fix `Kernel#raise` and don't override `cause` at exception re-raising (#3831, @andrykonchin).
+* Implement `rb_error_frozen_object` for the google-protobuf gem (@nirvdrum).
 
 Performance:
 

lib/truffle/truffle/cext.rb

@@ -2347,6 +2347,10 @@ def rb_eval_cmd_kw(cmd, args, kw_splat)
     end
   end
 
+  def rb_error_frozen_object(object)
+    raise FrozenError.new("can't modify frozen #{Primitive.class(self)}", receiver: self)
+  end
+
   def rb_tr_warn(message)
     location = caller_locations(1, 1)[0]
     message_with_prefix = "#{location.label}: warning: #{message}"

src/main/c/cext/error.c

@@ -49,3 +49,8 @@ bool rb_warning_category_enabled_p(rb_warning_category_t category) {
 void rb_tr_warn_va_list(const char *fmt, va_list args) {
   RUBY_CEXT_INVOKE("rb_tr_warn", rb_vsprintf(fmt, args));
 }
+
+void rb_error_frozen_object(VALUE frozen_obj) {
+    RUBY_CEXT_INVOKE_NO_WRAP("rb_error_frozen_object", frozen_obj);
+    UNREACHABLE;
+}

tool/generate-cext-trampoline.rb

@@ -13,6 +13,7 @@
 NO_RETURN_FUNCTIONS = %w[
   ruby_malloc_size_overflow
   rb_error_arity
+  rb_error_frozen_object
   rb_iter_break
   rb_iter_break_value
   rb_f_notimplement