Fix GH-22168: Silence phpdbg catch class fetch

Author: shamanzpua

sapi/phpdbg/phpdbg_utils.c

@@ -633,7 +633,7 @@ PHPDBG_API bool phpdbg_check_caught_ex(zend_execute_data *execute_data, zend_obj
 				zend_class_entry *ce;
 
 				if (!(ce = CACHED_PTR(cur->extended_value & ~ZEND_LAST_CATCH))) {
-					ce = zend_fetch_class_by_name(Z_STR_P(RT_CONSTANT(cur, cur->op1)), Z_STR_P(RT_CONSTANT(cur, cur->op1) + 1), ZEND_FETCH_CLASS_NO_AUTOLOAD);
+					ce = zend_fetch_class_by_name(Z_STR_P(RT_CONSTANT(cur, cur->op1)), Z_STR_P(RT_CONSTANT(cur, cur->op1) + 1), ZEND_FETCH_CLASS_NO_AUTOLOAD | ZEND_FETCH_CLASS_SILENT);
 					CACHE_PTR(cur->extended_value & ~ZEND_LAST_CATCH, ce);
 				}
 

sapi/phpdbg/tests/exceptions_004.phpt

@@ -0,0 +1,20 @@
+--TEST--
+GH-22168 (Exception caught by a later catch is not misreported as uncaught when an earlier catch references a non-existent class)
+--PHPDBG--
+r
+q
+--EXPECTF--
+[Successful compilation of %s]
+prompt> Caught it. 'handled' it
+[Script ended normally]
+prompt>
+--FILE--
+<?php declare(strict_types=1);
+
+try {
+    throw new RuntimeException();
+} catch (LibrarySpecificException) {
+    // A library specific exception. Not autoloaded since it did not happen.
+} catch (RuntimeException) {
+    echo "Caught it. 'handled' it\n";
+}