[clang] [clang-linker-wrapper][lit] Fix SPIR-V OpenMP ELF test (PR #126098)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-x86_64-debian-dylib` running on `gribozavr4` while building `clang` at step 6 "test-build-unified-tree-check-clang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/60/builds/19002

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-clang) failure: test (failure)
******************** TEST 'Clang :: Tooling/clang-linker-wrapper-spirv-elf.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 4: mkdir -p /b/1/llvm-x86_64-debian-dylib/build/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_tmp
+ mkdir -p /b/1/llvm-x86_64-debian-dylib/build/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_tmp
RUN: at line 5: cd /b/1/llvm-x86_64-debian-dylib/build/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_tmp
+ cd /b/1/llvm-x86_64-debian-dylib/build/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_tmp
RUN: at line 6: /b/1/llvm-x86_64-debian-dylib/build/bin/clang --driver-mode=g++ -fopenmp -fopenmp-targets=spirv64-intel -nogpulib -c -o /b/1/llvm-x86_64-debian-dylib/build/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_clang-linker-wrapper-spirv-elf.o /b/1/llvm-x86_64-debian-dylib/llvm-project/clang/test/Tooling/clang-linker-wrapper-spirv-elf.cpp
+ /b/1/llvm-x86_64-debian-dylib/build/bin/clang --driver-mode=g++ -fopenmp -fopenmp-targets=spirv64-intel -nogpulib -c -o /b/1/llvm-x86_64-debian-dylib/build/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_clang-linker-wrapper-spirv-elf.o /b/1/llvm-x86_64-debian-dylib/llvm-project/clang/test/Tooling/clang-linker-wrapper-spirv-elf.cpp
clang: error: unable to execute command: Executable "llvm-spirv" doesn't exist!
clang: error: llvm-spirv command failed with exit code 1 (use -v to see invocation)

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/126098