test which AppVeyor sometimes can't run.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66191 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

because it had already been SEGV-ed in pull request'S CI
https://ci.appveyor.com/project/ruby/ruby/builds/20427065/job/32oahrcd58b8ubb1
and has never worked on trunk either.

Please make sure it does not SEGVs on your MinGW environment or pull
request before enabling native fiber on MinGW.

appveyor.yml: reverted commits to make CI green with native fiber
test/excludes/_appveyor/msys2/TestArray.rb: ditto
test/excludes/_appveyor/msys2/TestEnumerable.rb: ditto
test/excludes/_appveyor/vs/TestArray.rb: ditto

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65892 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

https://ci.appveyor.com/project/ruby/ruby/builds/20432223/job/yhwbku8dg2s40e9e
C:/projects/ruby/test/lib/test/unit.rb:1004: warning: undefining `object_id' may cause serious problems
C:/projects/ruby/test/lib/test/unit.rb:1004: warning: undefining `__send__' may cause serious problems

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65891 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

because it SEGVs on setup like:
https://ci.appveyor.com/project/ruby/ruby/builds/20431217/job/97no5h1gqv50k1vf

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65889 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65886 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

because separately running it without -j didn't work.

Revert "appveyor.yml: run memory-exchausting test separately"
This reverts commit r65703.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65760 b2dd03c8-39d4-4d8f-98ff-823fe69b080e