mkmf.rb: CONFTEST

* lib/mkmf.rb (CONFTEST): constify hardcoded filename.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41769 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test_have_library.rb: toolchains result

* test/mkmf/test_have_library.rb (create_library): check if toolchains
  work.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41770 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
test/mkmf: $extmk in parallel test

* test/mkmf/base.rb, test/mkmf/test_config.rb: needs to set $extmk
  since worker processes in parallel test mode.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41771 b2dd03c8-39d4-4d8f-98ff-823fe69b080e