Merge branch '5.4' into 6.3

* 5.4:
  [Config] Prefixing FileExistenceResource::__toString() to avoid conflict with FileResource
  [String] Method toByteString conversion using iconv is unreachable
  [HttpKernel] Fix PHP deprecation

Author: nicolas-grekas

DataCollector/LoggerDataCollector.php

@@ -210,7 +210,7 @@ private function getContainerDeprecationLogs(): array
 
     private function getContainerCompilerLogs(string $compilerLogsFilepath = null): array
     {
-        if (!is_file($compilerLogsFilepath)) {
+        if (!$compilerLogsFilepath || !is_file($compilerLogsFilepath)) {
             return [];
         }