merge revision(s) 89242279,529fc204: [Backport #18141]

	Marshal.load: do not call the proc until strings have their encoding

	Ref: https://bugs.ruby-lang.org/issues/18141
	---
	 marshal.c                             |  7 +++-
	 spec/ruby/core/marshal/shared/load.rb | 62 +++++++++++++++++++++++------------
	 test/ruby/test_marshal.rb             | 17 ++++++++++
	 3 files changed, 64 insertions(+), 22 deletions(-)

	marshal.c: don't call the proc with partially initialized objects.
	 (#4866)

	For cyclic objects, it requires to keep a st_table of the partially
	initialized objects.
	---
	 marshal.c                             | 75 ++++++++++++++++++++---------------
	 spec/ruby/core/marshal/shared/load.rb | 75 ++++++++++++++++++++---------------
	 test/ruby/test_marshal.rb             | 12 ++++++
	 3 files changed, 97 insertions(+), 65 deletions(-)