[rfa] space reduction in gdbtypes.h

[Andrew Cagney]

>    /* FIXME, these should probably be restricted to a Fortran-specific
>       field in some fashion.  */
>  #define BOUND_CANNOT_BE_DETERMINED   5
> @@ -306,8 +306,8 @@
>  #define BOUND_BY_REF_IN_REG          2
>  #define BOUND_BY_VALUE_IN_REG        1
>  #define BOUND_SIMPLE                 0
> -  int upper_bound_type;
> -  int lower_bound_type;
> +  int upper_bound_type : 4;
> +  int lower_bound_type : 4;

Hmm, doesn't this part scream ENUM?  Without that the packing is unsafe: 
adding an extra variant that overflows the field won't be detected; 
compilers capable of checking enum assignments won't do anything useful.

enjoy,
Andrew