My last change made the test not run when the `spirv-tools` feature is
not available, which is always the case in CI for clang tests, but it
fails if `spirv-tools` is available for the following reasons:
1) We didn't build `spirv-link` as part of the internal `SPIRV-Tools`
build, which is required by the `clang` call in `clang-linker-wrapper`,
I already fixed that
[here](https://github.com/llvm/llvm-project/pull/126319).
2) We didn't depend on the `SPIRV-Tools` CMake targets in clang tests,
so depending on what CMake targets were built before running
`check-clang`, `SPIRV-Tools` might not have been built.
3) We didn't check for `llvm-spirv` being available, which is not part
of `SPIRV-Tools` but is currently required for SPIR-V compilation.
Manually confirmed this works. This test is the bane of my existence.
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Signed-off-by: Sarnie, Nick <nick.sarnie@intel.com>
c2fea0d837