merge revision(s) 7b9476fbfab738d1eb01b4b4c4af9a1680513019: [Backport #17642]

	Ractor.allocate should not be allowed

	Ractor.allocate and Ractor#dup should not be allowed like Thread.
	[Bug #17642]
	---
	 bootstraptest/test_ractor.rb | 18 ++++++++++++++++++
	 ractor.c                     |  2 ++
	 2 files changed, 20 insertions(+)

1 files changed, 2 insertions, 0 deletions

diff --git a/ractor.c b/ractor.c
index 420b2051b2..8de13954ce 100644
--- a/ractor.c
+++ b/ractor.c
@@ -2047,6 +2047,8 @@ void
 Init_Ractor(void)
 {
     rb_cRactor = rb_define_class("Ractor", rb_cObject);
+    rb_undef_alloc_func(rb_cRactor);
+
     rb_eRactorError          = rb_define_class_under(rb_cRactor, "Error", rb_eRuntimeError);
     rb_eRactorIsolationError = rb_define_class_under(rb_cRactor, "IsolationError", rb_eRactorError);
     rb_eRactorRemoteError    = rb_define_class_under(rb_cRactor, "RemoteError", rb_eRactorError);