Fix dll path issue with Ruby on windows

Signed-off-by: Addisu Z. Taddese <[email protected]>

src/cmd/cmdsdformat.rb.in

@@ -185,6 +185,15 @@ class Cmd
     end
     conf_version = LIBRARY_VERSION
 
+    if defined? RubyInstaller
+      # RubyInstaller does not search for dlls in PATH or the directory that tests are running from,
+      # so we'll add the parent directory of the plugin to the search path.
+      ENV['RUBY_DLL_PATH'] = ENV['PATH']
+      RubyInstaller::Runtime.enable_dll_search_paths
+      # https://github.com/oneclick/rubyinstaller2/wiki/For-gem-developers#-dll-loading
+      RubyInstaller::Runtime.add_dll_directory(File.dirname(plugin))
+    end
+
     begin
       Importer.dlload plugin
     rescue DLError => error