Use ENV['RUBY_EXE'] as RbConfig.ruby might be incorrect
Use ENV['RUBY_EXE'] as RbConfig.ruby might be incorrect

* On a built-but-not-installed-ruby.

git-svn-id: ab86ecd26fe50a6a239cacb71380e346f71cee7d@60529 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

eregon/rubyspec,eregon/rubyspec,nobu/rubyspec,nobu/rubyspec,ruby/rubyspec,ruby/spec,eregon/rubyspec,nobu/rubyspec,ruby/spec,ruby/spec,ruby/rubyspec