[libclc] [libclc] Fix a couple of issues preventing in-tree builds (PR #87505)

[Fraser Cormack via cfe-commits]

frasercrmck wrote:

> Thanks. Unfortunately, I'm still getting a build failure:
> 
> ```
> [1792/1922] cd /tmp/portage/dev-libs/libclc-19.0.0.9999/work/libclc_build && /usr/lib/llvm/17/bin/llvm-spirv --spirv-max-version=1.1 -o spirv-mesa3d-.spv builtins.link.spirv-mesa3d-
> FAILED: spirv-mesa3d-.spv /tmp/portage/dev-libs/libclc-19.0.0.9999/work/libclc_build/spirv-mesa3d-.spv 
> cd /tmp/portage/dev-libs/libclc-19.0.0.9999/work/libclc_build && /usr/lib/llvm/17/bin/llvm-spirv --spirv-max-version=1.1 -o spirv-mesa3d-.spv builtins.link.spirv-mesa3d-
> No such file or directory
> ```
> 
> It seems to be missing `.bc` suffix, I guess? Looking at the earlier mention, shouldn't it be `$<TARGET_FILE:${builtins_link_lib_tgt}>`?

Sorry, it should be properly fixed now - I was rushing things and that just made it worse. I hadn't noticed that the build I was testing hadn't found `llvm-spirv` and so those targets were missing. I've now built it locally successfully.

https://github.com/llvm/llvm-project/pull/87505