Support types that differ across C standards

[TravisCardwell]

How should we handle types that have different definitions across C standards?

I have found one so far: struct lconv, defined in locale.h.

In C89 (4.4 Localization), the following fields are defined:

char *decimal_point;       /* "." */
char *thousands_sep;       /* "" */
char *grouping;            /* "" */
char *int_curr_symbol;     /* "" */
char *currency_symbol;     /* "" */
char *mon_decimal_point;   /* "" */
char *mon_thousands_sep;   /* "" */
char *mon_grouping;        /* "" */
char *positive_sign;       /* "" */
char *negative_sign;       /* "" */
char int_frac_digits;      /* CHAR_MAX */
char frac_digits;          /* CHAR_MAX */
char p_cs_precedes;        /* CHAR_MAX */
char p_sep_by_space;       /* CHAR_MAX */
char n_cs_precedes;        /* CHAR_MAX */
char n_sep_by_space;       /* CHAR_MAX */
char p_sign_posn;          /* CHAR_MAX */
char n_sign_posn;          /* CHAR_MAX */

In C99 (7.11 Localization), the following fields were added:

char int_p_cs_precedes;    // CHAR_MAX
char int_n_cs_precedes;    // CHAR_MAX
char int_p_sep_by_space;   // CHAR_MAX
char int_n_sep_by_space;   // CHAR_MAX
char int_p_sign_posn;      // CHAR_MAX
char int_n_sign_posn;      // CHAR_MAX

Musl defines the structure with all of these fields, compliant with C99 and later.

What should we do in this case? Perhaps one option is to implement the versions as separate types and make the C standard a factor when resolving types.