[ruby/mmtk] Fix libmmtk_ruby.a building in extconf.rb
Since libmmtk_ruby.a was a PHONY target, it caused the shared object to not be rebuilt even though libmmtk_ruby.a was updated.
https://github.com/ruby/mmtk/commit/076f0a97a6
Added by
[ruby/mmtk] Fix libmmtk_ruby.a building in extconf.rb
Since libmmtk_ruby.a was a PHONY target, it caused the shared object to
not be rebuilt even though libmmtk_ruby.a was updated.
https://github.com/ruby/mmtk/commit/076f0a97a6