reduce feof() calls (#1041)

micro-optimization: when doing large file copies, this will reduce the number of feof() calls. for example, if copying 100MB, this will save approximately 25,599 feof() calls (255 feof() calls for every MB) - also feofs() may do an actual syscall, and syscalls are relatively expensive/time-consuming.

tinyfilemanager.php

@@ -971,7 +971,15 @@ if (!empty($_FILES) && !FM_READONLY) {
                     if ($in) {
                         if (PHP_VERSION_ID < 80009) {
                             // workaround https://bugs.php.net/bug.php?id=81145
-                            while (!feof($in)) { fwrite($out, fread($in, 4096)); }
+                            do {
+                                for (;;) {
+                                    $buff = fread($in, 4096);
+                                    if ($buff === false || $buff === '') {
+                                        break;
+                                    }
+                                    fwrite($out, $buff);
+                                }
+                            } while (!feof($in));
                         } else {
                             stream_copy_to_stream($in, $out);
                         }