[libclc] [libclc] Make library output directories explicit (PR #146833)

[Michał Górny via cfe-commits]

mgorny wrote:

This change broke installing symlinks. Now all symlinks are installed pointing to the build directory, i.e.:

```
-rw-r--r-- 1 root root  13M Jul 19 16:18 amdgcn--amdhsa.bc
lrwxrwxrwx 1 root root   82 Jul 19 16:18 bonaire-amdgcn--.bc -> /var/tmp/portage/llvm-core/libclc-22.0.0.9999/work/libclc_build/tahiti-amdgcn--.bc
lrwxrwxrwx 1 root root   92 Jul 19 16:18 bonaire-amdgcn-mesa-mesa3d.bc -> /var/tmp/portage/llvm-core/libclc-22.0.0.9999/work/libclc_build/tahiti-amdgcn-mesa-mesa3d.bc
lrwxrwxrwx 1 root root   82 Jul 19 16:18 carrizo-amdgcn--.bc -> /var/tmp/portage/llvm-core/libclc-22.0.0.9999/work/libclc_build/tahiti-amdgcn--.bc
lrwxrwxrwx 1 root root   92 Jul 19 16:18 carrizo-amdgcn-mesa-mesa3d.bc -> /var/tmp/portage/llvm-core/libclc-22.0.0.9999/work/libclc_build/tahiti-amdgcn-mesa-mesa3d.bc
```

and so on.

https://github.com/llvm/llvm-project/pull/146833