Fix bug #81630: Don't claim known hash in getTraitAliases()

We don't intern this string, and this code is not particularly
performance critical in the first place, so just drop the the
assumption.

Author: nikic

NEWS

@@ -9,6 +9,8 @@ PHP                                                                        NEWS
 - Reflection:
   . Fixed bug #81611 (ArgumentCountError when getting default value from
     ReflectionParameter with new). (Cameron Porter)
+  . Fixed bug #81630 (PHP 8.1: ReflectionClass->getTraitAliases() crashes with
+    Internal error). (Nikita)
 
 - XML:
   . Fixed bug #79971 (special character is breaking the path in xml function).

ext/reflection/php_reflection.c

@@ -5116,18 +5116,15 @@ ZEND_METHOD(ReflectionClass, getTraitAliases)
 
 				if (!class_name) {
 					uint32_t j = 0;
-					zval *zv;
-					zend_class_entry *trait;
 					zend_string *lcname = zend_string_tolower(cur_ref->method_name);
 
 					for (j = 0; j < ce->num_traits; j++) {
-						zv = zend_hash_find_known_hash(CG(class_table), ce->trait_names[j].lc_name);
-						if (zv) {
-							trait = Z_CE_P(zv);
-							if (zend_hash_exists(&trait->function_table, lcname)) {
-								class_name = trait->name;
-								break;
-							}
+						zend_class_entry *trait =
+							zend_hash_find_ptr(CG(class_table), ce->trait_names[j].lc_name);
+						ZEND_ASSERT(trait && "Trait must exist");
+						if (zend_hash_exists(&trait->function_table, lcname)) {
+							class_name = trait->name;
+							break;
 						}
 					}
 					zend_string_release_ex(lcname, 0);