Disable custom execute_ex during function JIT fuzzing as well

Having zend_execute_ex set is normally not a problem for the
function JIT, but there is an edge case leak due to special
RELEASE_THIS handling during generator creation. As this is an
unsupported mode of operation, reset to the original handler
for the function jit fuzzer as well.

Author: nikic

sapi/fuzzer/fuzzer-function-jit.c

@@ -38,8 +38,10 @@ int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
 		steps_left = MAX_STEPS;
 		zend_alter_ini_entry_chars(jit_option,
 			"function", sizeof("function")-1, PHP_INI_USER, PHP_INI_STAGE_RUNTIME);
+		zend_execute_ex = orig_execute_ex;
 		fuzzer_do_request_from_buffer(
 			FILE_NAME, (const char *) Data, Size, /* execute */ 1, opcache_invalidate);
+		zend_execute_ex = fuzzer_execute_ex;
 	}
 
 	zend_string_release(jit_option);