mkmf.rb: defer use of instance variable
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39717 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
mkmf.rb: defer use of instance variable
defer use of instance variable until needed. [Bug #8074]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39717 b2dd03c8-39d4-4d8f-98ff-823fe69b080e