merge revision(s) 1cdae49d39fbaef654df487f168d1fb14a146d59: [Backport #17577]

	Implement NameError::message#clone for Ractor

	---
	 bootstraptest/test_ractor.rb   | 13 +++++++++++++
	 error.c                        | 35 +++++++++++++++++++++++++++++++++--
	 test/objspace/test_objspace.rb |  9 +++++++++
	 3 files changed, 55 insertions(+), 2 deletions(-)

1 files changed, 9 insertions, 0 deletions

diff --git a/test/objspace/test_objspace.rb b/test/objspace/test_objspace.rb
index 230c1d0513..6b956e6d14 100644
--- a/test/objspace/test_objspace.rb
+++ b/test/objspace/test_objspace.rb
@@ -528,6 +528,15 @@ class TestObjSpace < Test::Unit::TestCase
     children.each {|child| ObjectSpace.internal_class_of(child).itself} # this used to crash
   end
 
+  def test_name_error_message
+    begin
+      bar
+    rescue => err
+      _, m = ObjectSpace.reachable_objects_from(err)
+    end
+    assert_equal(m, m.clone)
+  end
+
   def traverse_super_classes klass
     while klass
       klass = ObjectSpace.internal_super_of(klass)