Fix regression on systems built without JIT (php#16024)

regressing commit: 654b787

This was called if JIT was enabled or not. If not enabled, it'll result
in an undeclared function warning and maybe a bad time in the linker.
Gate the meat of this PHP-side function on if JIT is enabled (but keep
it existing so PHP userland code works with or without JIT, OFC).

Author: NattyNarwhal

Diff for: ext/opcache/zend_accelerator_module.c

@@ -934,10 +934,12 @@ ZEND_FUNCTION(opcache_jit_blacklist)
 		RETURN_THROWS();
 	}
 
+#ifdef HAVE_JIT
 	const zend_function *func = zend_get_closure_method_def(Z_OBJ_P(closure));
 	if (ZEND_USER_CODE(func->type)) {
 		zend_jit_blacklist_function((zend_op_array *)&func->op_array);
 	}
+#endif
 }
 
 ZEND_FUNCTION(opcache_compile_file)