added missing null check

for p_func inside _parse_function

modules/gdscript/gd_compiler.cpp

@@ -1218,7 +1218,7 @@ Error GDCompiler::_parse_function(GDScript *p_script,const GDParser::ClassNode *
 
 	bool is_initializer=!p_for_ready && !p_func;
 
-	if (is_initializer || String(p_func->name)=="_init") {
+	if (is_initializer || (p_func && String(p_func->name)=="_init")) {
 		//parse initializer for class members
 		if (!p_func && p_class->extends_used && p_script->native.is_null()){