Merge branch 'libbpf: btf typed data dumping fixes (__int128 usage, error propagation)'

Alan Maguire says:

====================

This series aims to resolve further issues with the BTF typed data
dumping interfaces in libbpf.

Compilation failures with use of __int128 on 32-bit platforms were
reported [1].  As a result, the use of __int128 in libbpf typed data
dumping is replaced with __u64 usage for bitfield manipulations.
In the case of 128-bit integer values, they are simply split into
two 64-bit hex values for display (patch 1).

Tests are added for __int128 display in patch 2, using conditional
compilation to avoid problems with a lack of __int128 support.

Patch 3 resolves an issue Andrii noted about error propagation
when handling enum data display.

More followup work is required to ensure multi-dimensional char array
display works correctly.

[1] https://lore.kernel.org/bpf/1626362126-27775-1-git-send-email-alan.maguire@oracle.com/T/#mc2cb023acfd6c3cd0b661e385787b76bb757430d

Changes since v1:

 - added error handling for bitfield size > 64 bits by changing function
   signature for bitfield retrieval to return an int error value and to set
   bitfield value via a __u64 * argument (Andrii)
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>