Disable frameless calls when observers are enabled

Author: iluuu1994

Zend/zend_compile.c

@@ -4549,6 +4549,10 @@ static int find_frameless_function_offset(int arity, void *handler)
 
 static zend_result zend_compile_frameless_icall(znode *result, zend_ast_list *args, zend_function *fbc, uint32_t type)
 {
+	if (ZEND_OBSERVER_ENABLED) {
+		return FAILURE;
+	}
+
 	if (type != BP_VAR_R) {
 		return FAILURE;
 	}

ext/zend_test/tests/observer_frameless.phpt

@@ -0,0 +1,17 @@
+--TEST--
+Observer: Frameless calls are disabled when there are observers
+--EXTENSIONS--
+zend_test
+--INI--
+zend_test.observer.enabled=1
+--FILE--
+<?php
+function _strpos(string $str) {
+    return \strpos($str, 1, 1);
+}
+_strpos('foo');
+?>
+--EXPECTF--
+<!-- init '%s' -->
+<!-- init _strpos() -->
+<!-- init strpos() -->