spec/ruby/core/hash/transform_keys_spec.rb: Fix the failure of
	 ruby_3_0

	https://github.com/ruby/spec/pull/833
	https://github.com/ruby/spec/commit/8290e5ad8952b14ee9a5069651d9864c66681112
	---
	 spec/ruby/core/hash/transform_keys_spec.rb | 4 ++--
	 1 file changed, 2 insertions(+), 2 deletions(-)

	Keep non evaluated keys in `Hash#transform_keys!` [Bug #17735]

	---
	 hash.c                                     |  6 +++++-
	 spec/ruby/core/hash/transform_keys_spec.rb | 12 +++++++++++-
	 test/ruby/test_hash.rb                     |  8 ++++++++
	 3 files changed, 24 insertions(+), 2 deletions(-)

	Clear an intermediate hash [Bug #17735]

	---
	 hash.c | 1 +
	 1 file changed, 1 insertion(+)

	Hide an intermediate array

	---
	 hash.c | 6 ++++--
	 1 file changed, 4 insertions(+), 2 deletions(-)

	Force recycle intermediate collection in Hash#transform_keys! [Bug
	 #17735]

	* Force recycle intermediate hash

	* Force recycle intermediate array too

	https://github.com/ruby/ruby/pull/4329#issuecomment-808840718
	---
	 hash.c | 2 ++
	 1 file changed, 2 insertions(+)

[Feature #15822]

Has been deprecated since 0c97c8e33584e6203bb09c08f92b63bd2cca8ae7.