* instruby.rb: moved into tool/.

* mkconfig.rb: ditto.

* rubytest.rb: ditto.

* runruby.rb: ditto.

* common.mk: follows the moves.

* configure.in: ditto.

* win32/Makefile.sub: ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@23542 b2dd03c8-39d4-4d8f-98ff-823fe69b080e