add some gcc builtin float types

src/parser/parser.cc

@@ -202,6 +202,15 @@ void observe_type_name(const std::string & type_name)
 
 static const char * builtin_types[] = {
     "__builtin_va_list",
+    "__float128",
+    "_Float128",
+    "_Float64",
+    "_Float64x",
+    "_Float32x",
+    "_Float16",
+    "__float80",
+    "__ibm128",
+    "_Complex",
 };
 
 bool is_type_name(const std::string & type_name)