Add build:<build variant>:clean to cleanup a specific build artifacts

Author: kateinoigakukun

lib/ruby_wasm/build_system/product/crossruby.rb

@@ -147,6 +147,13 @@ def build(remake: false, reconfigure: false)
       system "tar cfz #{artifact} -C rubies #{name}"
     end
 
+    def clean
+      FileUtils.rm_rf dest_dir
+      FileUtils.rm_rf build_dir
+      FileUtils.rm_rf ext_build_dir
+      FileUtils.rm_f artifact
+    end
+
     def name
       @params.name
     end

lib/ruby_wasm/rake_task.rb

@@ -78,6 +78,9 @@ def initialize(
       task :reconfigure do
         @crossruby.build(reconfigure: true)
       end
+      task :clean do
+        @crossruby.clean
+      end
     end
   end