fix some test skipping

Author: sirreal

tests/phpunit/tests/html-api/wpHtmlProcessorHtml5lib.php

@@ -139,7 +139,7 @@ public static function build_html5_treelike_string( $fragment_context, $html ) {
 		$indent       = '  ';
 
 		while ( $processor->next_token() ) {
-			if ( $processor->get_last_error() !== null ) {
+			if ( ! is_null( $processor->get_last_error() ) ) {
 				return null;
 			}
 
@@ -205,10 +205,6 @@ public static function build_html5_treelike_string( $fragment_context, $html ) {
 			}
 		}
 
-		if ( WP_HTML_Processor::ERROR_UNSUPPORTED === $processor->get_last_error() ) {
-			return null;
-		}
-
 		if ( $processor->paused_at_incomplete_token() ) {
 			return null;
 		}