decl_AddDS
decl_AddDS(dp, $1, &errstr);
$$ = decl_AddDS($2, $1, &ep);
$$ = decl_AddDS($2, $1, &ep);
$$ = decl_AddDS(decl_Construct(), $1, &ep);
static decl_t *decl_AddDS(decl_t *, decl_spec_t *, const char **);