Ignore stdbool compat symbols when introspecting
The introspection scanner should ignore the C89 backward compatibility
symbols for the _Bool type, to avoid constants like `true` and `false`
appearing in the generated introspection data.
Fixes:
#endif
#if defined(_MSC_VER) && !defined(__bool_true_false_are_defined) && (_MSC_VER < 1800)
+# ifndef __GI_SCANNER__
typedef int bool;
# define false 0
# define true 1
+# endif
#else
# include <stdbool.h>
#endif
