libclc: CMakeCLCCompiler check doesn't work

Despite
` clang -print-targets`
```
spirv - SPIR-V Logical
spirv32 - SPIR-V 32-bit
spirv64 - SPIR-V 64-bit
```
libclc can't configure itself after https://github.com/llvm/llvm-project/pull/185243/changes:

```
CMake Error at cmake/modules/CMakeTestCLCCompiler.cmake:29 (message):
The CLC compiler

/usr/bin/cc

is not able to compile a simple OpenCL test program.
```

BTW: When building libclc 22.1.8 there are diagnostics:
```
[5035/5161] Generating clspv64--.bc
/usr/bin/opt: WARNING: failed to create target machine for 'spir64-unknown-unknown': unable to get target for 'spir64-unknown-unknown', see --version and --triple.
[5036/5161] Generating clspv--.bc
/usr/bin/opt: WARNING: failed to create target machine for 'spir-unknown-unknown': unable to get target for 'spir-unknown-unknown', see --version and --triple.
```

Start with cmake/modules/CMakeTestCLCCompiler.cmake and reproduce the configuration failure using the reported clang target list. Then inspect the libclc 22.1.8 diagnostics from opt for spir and spir64. Done means libclc can configure and compile its simple OpenCL test without the reported CLC compiler failure.

Written by the indexing model from the issue text.