[ruby-cvs:69175] mame:r61994 (trunk): ext/ripper/tools/dsl.rb: Use String#sub instead of delete_suffix

[mame at ruby-lang.org]

mame	2018-01-21 02:52:51 +0900 (Sun, 21 Jan 2018)

  New Revision: 61994

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=61994

  Log:
    ext/ripper/tools/dsl.rb: Use String#sub instead of delete_suffix
    
    It fails when baseruby is old.

  Modified files:
    trunk/ext/ripper/tools/dsl.rb