Hi,

by now I also tested it on overdrive1, an aarch64 machine.

> I do not have access to a real aarch64 machine--so no idea how it is there.
> That would be the most interesting case, because those don't have X86_32,
> so ILP32 is either not present or implemented differently.

I added it in the table below under "a64armhf".

ILP32 is not present on aarch64.

Test result of [1] updated:

system   _FILE_OFFSET_BITS off_t   d_off-sizeof   d_off-values
---------------------------------------------------------------
x86_64   -                 8 Byte  8 Byte         8 Byte
i686     -                 4 Byte  4 Byte         4 Byte
i686     64                8 Byte  8 Byte         4 Byte
i686     32                4 Byte  4 Byte         4 Byte
i686     7                 4 Byte  4 Byte         4 Byte
armhf    -                 4 Byte  4 Byte         4 Byte
armhf    64                8 Byte  8 Byte         4 Byte
armhf    32                4 Byte  4 Byte         4 Byte
armhf    7                 4 Byte  4 Byte         4 Byte
a64armhf -                 4 Byte  4 Byte         FAIL
a64armhf 64                8 Byte  8 Byte         8 Byte
a64armhf 32                4 Byte  4 Byte         FAIL
a64armhf 7                 4 Byte  4 Byte         FAIL

For a64armhf, the version with -D_FILE_OFFSET_BITS=64 is the only one where
readdir succeeds on my specially-prepared directory.