sys/resource.h 's struct-of-unions completely foils gcc & zig header analysis

bits_types_struct_rusage_h.ads

-- gcc -c -fdump-ada-spec "getr.h" -C  # where getr.h is #include <sys/resource.h>
...
   pragma Convention (C_Pass_By_Copy, anon1055_anon1068_union);
   pragma Unchecked_Union (anon1055_anon1068_union);type anon1055_anon1069_union (discr : unsigned := 0) is record
      case discr is
         when 0 =>
            ru_nivcsw : aliased long;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:281
         when others =>
            uu_ru_nivcsw_word : aliased x86_64_linux_gnu_bits_types_h.uu_syscall_slong_t;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:282
      end case;
   end record;
   pragma Convention (C_Pass_By_Copy, anon1055_anon1069_union);
   pragma Unchecked_Union (anon1055_anon1069_union);type rusage is record
      ru_utime : aliased x86_64_linux_gnu_bits_time_h.timeval;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:190
      ru_stime : aliased x86_64_linux_gnu_bits_time_h.timeval;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:192
      anon1845 : aliased anon1055_anon1056_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:198
      anon1849 : aliased anon1055_anon1057_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:206
      anon1853 : aliased anon1055_anon1058_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:212
      anon1857 : aliased anon1055_anon1059_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:218
      anon1861 : aliased anon1055_anon1060_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:225
      anon1865 : aliased anon1055_anon1061_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:231
      anon1869 : aliased anon1055_anon1062_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:237
      anon1873 : aliased anon1055_anon1063_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:244
      anon1877 : aliased anon1055_anon1064_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:250
      anon1881 : aliased anon1055_anon1065_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:256
      anon1885 : aliased anon1055_anon1066_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:262
      anon1889 : aliased anon1055_anon1067_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:268
      anon1893 : aliased anon1055_anon1068_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:276
      anon1897 : aliased anon1055_anon1069_union;  -- /usr/include/x86_64-linux-gnu/bits/resource.h:283
   end record;

rusage.zig

// zig translate-c /usr/include/sys/resource.h|perl -lne 'print if /pub const struct_rusage/ .. /^}/'
pub const struct_rusage = extern struct.{
    ru_utime: struct_timeval,
    ru_stime: struct_timeval,
    @"": extern union.{
        ru_maxrss: c_long,
        __ru_maxrss_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_ixrss: c_long,
        __ru_ixrss_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_idrss: c_long,
        __ru_idrss_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_isrss: c_long,
        __ru_isrss_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_minflt: c_long,
        __ru_minflt_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_majflt: c_long,
        __ru_majflt_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_nswap: c_long,
        __ru_nswap_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_inblock: c_long,
        __ru_inblock_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_oublock: c_long,
        __ru_oublock_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_msgsnd: c_long,
        __ru_msgsnd_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_msgrcv: c_long,
        __ru_msgrcv_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_nsignals: c_long,
        __ru_nsignals_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_nvcsw: c_long,
        __ru_nvcsw_word: __syscall_slong_t,
    },
    @"": extern union.{
        ru_nivcsw: c_long,
        __ru_nivcsw_word: __syscall_slong_t,
    },
};