[ruby/readline] Suppress constant redefinition warning
When already set by use_lib_reline in test/readline/helper.rb of readline-ext.
use_lib_reline
https://github.com/ruby/readline/commit/0e3ca3b217
Added by nobu (Nobuyoshi Nakada) almost 4 years ago
[ruby/readline] Suppress constant redefinition warning
When already set by
use_lib_relinein test/readline/helper.rb ofreadline-ext.
https://github.com/ruby/readline/commit/0e3ca3b217