merge revision(s) 34840:
* configure.in (debugflags): check if -ggdb is accepted. [ruby-core:42875][Bug #6080]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@34841 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 34840:
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@34841 b2dd03c8-39d4-4d8f-98ff-823fe69b080e