Previously, the frozen check happened on `RCLASS_ORIGIN(self)`, which
can return an iclass. The frozen check is supposed to respond to objects
that users can call methods on while iclasses are hidden from users.
Other mutation methods like Module#{define_method,alias_method,public}
don't do this. Check frozen status on the module itself.

Fixes [Bug #19164] and [Bug #19166].

Co-authored-by: Alan Wu <XrXr@users.noreply.github.com>

Investigating:
http://ci.rvm.jp/logfiles/brlog.trunk-mjit.20220906-025646
which is not immediately reproducible on my laptop.

Fixes case where Object includes a module that defines a constant,
then using class/module keyword to define the same constant on
Object itself.

Implements [Feature #18832]

Implements [Feature #12655]

Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>

Previously in some when classes were duped (specifically those with a
prepended module), they would not correctly have their "superclasses"
array or depth filled in.

This could cause ancestry checks (like is_a? and Module comparisons) to
return incorrect results.

This happened because rb_mod_init_copy builds origin classes in an order
that doesn't have the super linked list fully connected until it's
finished. This commit fixes the previous issue by calling
rb_class_update_superclasses before returning the cloned class. This is
similar to what's already done in make_metaclass.

[Feature #17881]

Works similarly to `method_added` but for constants.

```ruby
Foo::BAR = 42 # call Foo.const_added(:FOO)
class Foo::Baz; end # call Foo.const_added(:Baz)
Foo.autoload(:Something, "path") # call Foo.const_added(:Something)
```

Co-authored-by: Nobuyoshi Nakada <nobu@ruby-lang.org>

This is to allow Module subclasses that include modules before
calling super in the subclass's initialize.

Remove rb_module_check_initializable from Module#initialize.
Module#initialize only calls module_exec if a block is passed,
it doesn't have other issues that would cause problems if
called multiple times or with an already initialized module.

Move initialization of super to Module#allocate, though I'm not
sure it is required there.  However, it's needed to be removed
from Module#initialize for this to work.

Fixes [Bug #18292]