Fix outdated check with platform fallback specs

Author: rwstauner

bundler/lib/bundler/cli/outdated.rb

@@ -77,7 +77,7 @@ def run
         gemfile_specs + dependency_specs
       end
 
-      specs.sort_by(&:name).uniq(&:name).each do |current_spec|
+      specs_for_outdated_check(specs).each do |current_spec|
         next unless gems.empty? || gems.include?(current_spec.name)
 
         active_spec = retrieve_active_spec(definition, current_spec)
@@ -152,6 +152,12 @@ def nothing_outdated_message
       end
     end
 
+    def specs_for_outdated_check(specs)
+      specs.group_by(&:name).values.filter_map do |matching_specs|
+        MatchPlatform.select_best_platform_match(matching_specs, Bundler.local_platform).first || matching_specs.first
+      end.sort_by(&:name)
+    end
+
     def retrieve_active_spec(definition, current_spec)
       active_spec = definition.resolve.find_by_name_and_platform(current_spec.name, current_spec.platform)
       return unless active_spec