Ruby » Ruby master

eval.c: fix circular cause

• eval.c (exc_setup_cause): always set cause of cause to get rid
  of circular references. [ruby-core:78688] [Bug #13043]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57137 b2dd03c8-39d4-4d8f-98ff-823fe69b080e