alias_method is private on Ruby 2.3 and 2.4 #149

Job	Run time
ruby-versions / Generate Ruby versions	3s
ubuntu-20.04 2.3	3m 12s
ubuntu-20.04 2.4	1m 36s
ubuntu-20.04 2.5	1m 17s
ubuntu-20.04 2.6	1m 20s
ubuntu-20.04 2.7	1m 32s
ubuntu-20.04 3.0	36s
ubuntu-20.04 3.1	33s
ubuntu-20.04 3.2	27s
ubuntu-20.04 head	42s
ubuntu-20.04 jruby	1m 48s
ubuntu-20.04 jruby-head	1m 49s
ubuntu-20.04 truffleruby	1m 3s
ubuntu-20.04 truffleruby-head	1m 31s
ubuntu-22.04 2.3	1m 7s
ubuntu-22.04 2.4	1m 31s
ubuntu-22.04 2.5	1m 17s
ubuntu-22.04 2.6	1m 24s
ubuntu-22.04 2.7	1m 15s
ubuntu-22.04 3.0	26s
ubuntu-22.04 3.1	27s
ubuntu-22.04 3.2	27s
ubuntu-22.04 head	42s
ubuntu-22.04 jruby	1m 19s
ubuntu-22.04 jruby-head	1m 53s
ubuntu-22.04 truffleruby	1m 10s
ubuntu-22.04 truffleruby-head	1m 14s
macos-11 2.3	3m 27s
macos-11 2.4	2m 7s
macos-11 2.5	2m 20s
macos-11 2.6	2m 10s
macos-11 2.7	2m 24s
macos-11 3.0	44s
macos-11 3.1	39s
macos-11 3.2	43s
macos-11 head	40s
macos-11 jruby	1m 29s
macos-11 jruby-head	1m 22s
macos-11 truffleruby	2m 8s
macos-11 truffleruby-head	2m 16s
macos-12 2.3	2m 12s
macos-12 2.4	2m 0s
macos-12 2.5	2m 34s
macos-12 2.6	2m 12s
macos-12 2.7	2m 1s
macos-12 3.0	37s
macos-12 3.1	36s
macos-12 3.2	35s
macos-12 head	43s
macos-12 jruby	1m 16s
macos-12 jruby-head	1m 42s
macos-12 truffleruby	1m 54s
macos-12 truffleruby-head	1m 42s
windows-latest 2.3	2m 56s
windows-latest 2.4	3m 27s
windows-latest 2.5	5m 6s
windows-latest 2.6	5m 46s
windows-latest 2.7	3m 36s
windows-latest 3.0	1m 40s
windows-latest 3.1	2m 6s
windows-latest 3.2	1m 13s
windows-latest head	1m 26s
ubuntu-latest jruby-9.1	1m 40s
ubuntu-latest jruby-9.2	1m 56s
ubuntu-latest jruby-9.3	1m 22s
	1h 46m 28s

Provide feedback