[clang] [llvm] [offload-arch] Move GPU detection into a library and unit tests to unittests/tools (PR #226552)

[Krzysztof Parzyszek via cfe-commits]

kparzysz wrote:

There are errors linking this code:
```
AMDGPUArchByHIP.cpp:(.text._Z14printGPUsByHIPv+0x64): undefined reference to `Verbose'
/usr/bin/ld: AMDGPUArchByHIP.cpp:(.text._Z14printGPUsByHIPv+0x75f): undefined reference to `Verbose'
/usr/bin/ld: AMDGPUArchByHIP.cpp:(.text._Z14printGPUsByHIPv+0x1195): undefined reference to `Verbose'
```

Please take a look asap.

https://github.com/llvm/llvm-project/pull/226552