Add script dependencies undetectable by build tools

Some scripts have dependencies that are undetectable by the webpack
plugin used to generate the dependency files. Add these dependencies
to the generated dependencies.

lib/client-assets.php

@@ -194,6 +194,17 @@ function gutenberg_register_packages_scripts() {
 			? json_decode( file_get_contents( $dependencies_file ) )
 			: array();
 
+		// Add dependencies that cannot be detected and generated by build tools.
+		switch ( $handle ) {
+			case 'wp-block-library':
+				array_push( $dependencies, 'editor' );
+				break;
+
+			case 'wp-edit-post':
+				array_push( $dependencies, 'media-models', 'media-views', 'postbox' );
+				break;
+		}
+
 		// Get the path from Gutenberg directory as expected by `gutenberg_url`.
 		$gutenberg_path = substr( $path, strlen( gutenberg_dir_path() ) );