In included file: unknown type name '__value_in_regs'

Keil Studio
1

I’m migrating some code over to Keil Studio (OS2) and ,

#include "mbed.h"

indicates an error;

“owner”: “generated_diagnostic_collection_name#a49c44c8-13e1-461d-9612-57b6c0e6a580”,
“code”: “unknown_typename”,
“severity”: 1,
“message”: “In included file: unknown type name ‘__value_in_regs’”,
“source”: “clang”,
“startLineNumber”: 1,
“startColumn”: 9,
“endLineNumber”: 1,
“endColumn”: 17

It complies and works.
Any way to get rid of it?