[PATCH] Fix refinement modification of method visibility in superclass

	Previously, this didn't work correctly, resulting in a
	SystemStackError. This fixes the issue by finding the related
	superclass method entry, and updating the orig_me in the
	refinement method to point to the superclass method.

	Fixes [Bug #21446]

	[PATCH] [Bug #21673] Fix resolving refined module-defined method

	A method defined in a module has no `defined_class`, use the ICLASS
	for it as the `defined_class`.

	[PATCH] Add test for [Bug #21265]

	The crash was fixed by a4dff09be79b52288a47658964d25e5aa84fc960 ("Fix
	resolving refined module-defined method"). I had a patch for this around
	for a few months but never merged it. Oops!

[Feature #20901]

The keyword tries to remove a method of the same name which is unlikely
to be the intention of this test:

    $ ruby -e 'undef Object'
    -e:1:in '<main>': undefined method 'Object' for class 'Object' (NameError)

Found looking at GH-11497. The NameError triggers error_highlight, which
loads a bunch of file under GC.stress set by this test when using Prism.
That takes a long time, causing a timeout.

As preparation for https://bugs.ruby-lang.org/issues/20205
making sure the test suite is compatible with frozen string
literals is making things easier.

In cfd7729ce7a31c8b6ec5dd0e99c67b2932de4732 we started using inline
caches for refinements. However, we weren't clearing inline caches when
defined on a reopened refinement module.

Fixes [Bug #20246]

In the following code, the iclass tree of refinements in cref should be <iclass of Kernel@M2> -> <iclass of Kernel@M1> -> Kernel.

However, the iclass tree was broken because of code for included modules of refinements in rb_using_refinement().
Refinement#include is now removed, so this commit removes such unnecessary code.

```ruby
module M1
  refine(Kernel) do
    def f1 = :f1
  end
end

module M2
  refine(Kernel) do
    def f2 = :f2
  end
end

class Foo
  using M1
  using M2

  def test
    p f2 #=> :f2

    p f1 # expected => :f1
         # actual => undefined local variable or method 'f1' for an instance of Foo
  end
end

Foo.new.test
```

Previously, we didn't invalidate the method entry wrapped by
VM_METHOD_TYPE_REFINED method entries which could cause calls to
land in the wrong method like it did in the included test.

Do the invalidation, and adjust rb_method_entry_clone() to accommodate
this new invalidation vector.

Fix: cfd7729ce7a31c8b6ec5dd0e99c67b2932de4732
See-also: e201b81f79828c30500947fe8c8ea3c515e3d112