LLVM offload compress

[Cordell Bloor <cgmb@slerp.xyz>]

Hello,

It seems that LLVM 18 has introduced the --offload-compress option [1]. 
This allows LLVM to use zlib or zstd compression on the AMD GPU code 
embedded within shared object libraries. They will be decompressed by 
the HIP runtime when needed. As GPU code tends to be very repetitive, 
it's likely that this will result in a space savings >90% for many of 
the largest ROCm libraries. That would be a dramatic reduction for the 
installed size on disk.

The ROCm 6.2 release is based upon LLVM 18, so this is probably 
something we should explore adding to the build flags once we get the 
HIP runtime updated.

Sincerely,
Cory Bloor

[1]: 
https://clang.llvm.org/docs/ClangOffloadBundler.html#compression-and-decompression