[ruby/psych] Add test for anchor reuse
The spec calls this a "reuse" of an anchor https://yaml.org/spec/1.2.2/#71-alias-nodes
https://github.com/ruby/psych/commit/57e3b70a56
[ruby/psych] Add test for anchor reuse
The spec calls this a "reuse" of an anchor
https://yaml.org/spec/1.2.2/#71-alias-nodes
https://github.com/ruby/psych/commit/57e3b70a56