merge revision(s) 47820: [Backport #10330]
* error.c: update exception tree. [DOC] reported by @hemge via twitter.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@47932 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 47820: [Backport #10330]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@47932 b2dd03c8-39d4-4d8f-98ff-823fe69b080e