merge revision(s) 94cea3e4,aa53d69a,6b7d32a5,c6319026,aa490f94: [Backport #18435]

	Fix {Method,UnboundMethod}#super_method for zsuper methods

	* We need to resolve the zsuper method first, and then look the super
	  method of that.
	---
	 proc.c                                            | 25 ++++++++++++-----------
	 spec/ruby/core/method/super_method_spec.rb        | 15 +++-----------
	 spec/ruby/core/unboundmethod/super_method_spec.rb | 16 ++++++---------
	 3 files changed, 22 insertions(+), 34 deletions(-)

	Add specs for {Method,UnboundMethod}#owner of a zsuper method

	---
	 spec/ruby/core/method/owner_spec.rb        | 6 ++++++
	 spec/ruby/core/unboundmethod/owner_spec.rb | 7 +++++++
	 2 files changed, 13 insertions(+)

	Resolve zsuper method during lookup but preserve owner separately

	* See https://bugs.ruby-lang.org/issues/18729#note-34
	* See [Bug #18729]
	---
	 proc.c                   | 109 +++++++++++++++++++++++++----------------------
	 test/ruby/test_method.rb |  66 +++++++++++++++++++++++-----
	 2 files changed, 114 insertions(+), 61 deletions(-)

	Extend tests for a zsuper method of which the method it resolved to
	 has been removed

	---
	 test/ruby/test_method.rb | 41 +++++++++++++++++++++++++++++++++++++++++
	 1 file changed, 41 insertions(+)

	Reduce diff to proc.c @ b0b9f720

	* So it's easy to review https://github.com/ruby/ruby/pull/6242 +
	  https://github.com/ruby/ruby/pull/6467 and there are less changes
	  overall.
	---
	 proc.c                   | 76 ++++++++++++++++++------------------------------
	 test/ruby/test_method.rb |  7 +++--
	 2 files changed, 34 insertions(+), 49 deletions(-)