[clang] [AMDGPU] Remove Code Object V3 (PR #67118)

[Andrew Stubbs via cfe-commits]

ams-cs wrote:

@Pierre-vh Can we undo this please? Just for now.

This broke the GCC build (which uses llvm-mc) because we still use v3 like @tob2 said. I don't know that anyone is using Fiji in production, but it's still a good proportion of what we have in our compiler test farm.

As far as I know, the last good ROCm for that device was 3.8 which doesn't support v4.

I appreciate that this isn't ideal; I'd like to remove that device too.

https://github.com/llvm/llvm-project/pull/67118