[clang] [HIP] compressed bundle format defaults to v3 (PR #152600)

[Yaxun Liu via cfe-commits]

yxsamliu wrote:

> Random question, what would compression look like for the offload binaries? I'm wondering how difficult it would be to switch HIP to using those instead of the bundles for its binary format.

There has been efforts to compress arbitrary ELF sections (https://maskray.me/blog/2023-07-07-compressed-arbitrary-sections), however, it may take time. Also, it may not apply to COFF on Windows. To achieve high compression ratio, using zstd to compress all code objects together is critical, therefore need a format that aggregates all code objects and compress them together.

https://github.com/llvm/llvm-project/pull/152600