merge revision(s) 67217: [Backport #15658]
The combination of non-Symbol keys and Symbol keys is now allowed again Revert r64358. [Bug #15658]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_6@67220 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 67217: [Backport #15658]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_6@67220 b2dd03c8-39d4-4d8f-98ff-823fe69b080e