Add a cache clear option for plugin cache.

Author: weitzman

src/Commands/core/CacheCommands.php

@@ -250,6 +250,7 @@ public function getTypes($include_bootstrapped_types = false)
                 'router' => [$this, 'clearRouter'],
                 'css-js' => [$this, 'clearCssJs'],
                 'render' => [$this, 'clearRender'],
+                'plugin' => [$this, 'clearPlugin'],
             ];
         }
 
@@ -297,6 +298,11 @@ public static function clearRender()
         Cache::invalidateTags(['rendered']);
     }
 
+    public static function clearPlugin()
+    {
+        \Drupal::getContainer()->get('plugin.cache_clearer')->clearCachedDefinitions();
+    }
+
     /**
      * Loads the Drupal autoloader and returns the instance.
      */